These include neutron beam radiation, hyperthermia, radiosensitizers, and altered radiation fractionation schemes. Radioprotectors 263,264 and 265,268 (discussed earlier in Dietary Supplements and Radioprotectors) and three-dimensional treatment planning 255 (discussed earlier in Three-Dimensional Radiation Treatment Planning) already have been described. The results of two randomized trials that have compared neutrons and photons in patients with unresectable and recurrent rectal cancers were reported by Duncan et al. Not only were no significant differences in local control or survival detected, but patients who received neutrons experienced higher acute and long-term grade 3+ skin toxicity. The preferential absorption in fat of neutrons may have contributed to the complications seen in the skin and subcutaneous tissues. Similar severe and fatal complications were reported in a series of 25 patients with advanced rectal cancer treated by Battermann et al. Despite the theoretical advantages, little interest has been shown in the treatment of rectal cancer with neutrons. When combined with adjuvant postoperative radiation therapy, it significantly decreases local failure compared with radiation therapy alone. The repair of subcellular injury, regeneration, cell-cycle redistribution, and reoxygenation are all factors at the cellular level contributing to differences in how various normal tissues and tumors respond to fractionated radiation. The use of hyperfractionation and accelerated fractionation schemes take advantage of some of these factors. The late effects should be the same as or, more likely, less than conventional fractionation schemes. The major limitation of accelerated hyperfractionation is acute normal tissue toxicity. Because it is unlikely that these altered fractionation schemes can be combined with adequate doses of systemic chemotherapy, Movsas and colleagues 298 have limited the hyperfractionated portion to the boost. In a randomized trial of patients receiving radiation therapy for pelvic malignancies, three-dimensional conformal radiation therapy decreased the volume of normal tissue in the field, but did not decrease acute toxicity. Because the natural history of these patients is dependent on a variety of factors, such as the volume and site(s) of metastatic disease and, in those with recurrent disease, the disease-free interval, treatment recommendations are individualized and no standard of care has been established. At Memorial Sloan-Kettering, the general approach is to deliver preoperative combined modality therapy both as a therapeutic measure and to help identify those who may benefit from an aggressive surgical approach. If after the completion of therapy a response has been seen in both the primary and metastatic site(s), then the patient is evaluated, on a case by case basis, for surgery of the primary and metastasis. An important aspect of this follow-up is management of treatment-related problems and assessment for local-regional recurrences. These may have an impact on quality of life that is not apparent from survival statistics. Dietary modifications, including the use of a fiber supplement, may be necessary for management of bowel function. This management can occur on an ongoing basis during follow-up, because these symptoms are most profound during the initial year after treatment and tend to abate during the latter part of the follow-up period. In addition, patients who undergo creation of ostomies for their colorectal cancer management benefit from consultation with an enterostomal therapist. Counseling and appropriate referral for the management of sexual or bowel dysfunction can occur during follow-up visits. In most patients, recurrent disease is multifocal and treated with systemic chemotherapy. A chief symptom requiring palliation in patients with recurrent rectal carcinoma is obstruction. The use of salvage surgery for recurrence after local excision is presented in Recurrent Disease, earlier in this chapter. The use of surgery for lung metastases or hepatic metastases is discussed in Chapter 52. Frequently, patients in this circumstance are markedly debilitated and very poor surgical risks. These circumstances often make the risks of surgical intervention prohibitive, especially in light of the limited potential for survival. Palliative pelvic irradiation is a useful technique in patients who have not undergone previous radiotherapy. Palliative endoscopic placement of self-expanding metallic stents has also been used as an alternative to palliative colostomy.
While toremifene has been shown to be equivalent to tamoxifen in the metastatic setting, 639 its activity in the adjuvant setting has not been established. There are insufficient data to support the use of any other antiestrogens as adjuvant treatment for early-stage breast cancer, including raloxifene. In postmenopausal women, ongoing studies are evaluating aromatase inhibitors in place of tamoxifen, in conjunction with tamoxifen, and following 2 to 5 years of tamoxifen. Given the activity of aromatase inhibitors in the metastatic setting, these agents may ultimately play a role in the adjuvant therapy of postmenopausal women. Since the 1970s, randomized trials have addressed many fundamental questions related to adjuvant chemotherapy. Adjuvant chemotherapy initially was administered to women with positive nodes; a series of trials published in the late 1980s extended the use of adjuvant chemotherapy to node-negative women as well. Both studies showed a statistically significant improvement in disease-free survival, with subset analyses strongly suggesting most of the benefit was in women under the age of 50. The studies demonstrated a trend toward improved survival with chemotherapy, although the survival comparisons did not reach statistical significance. Many of these trials have been substantially larger than the early studies, thereby increasing the power of the trials to detect small but clinically meaningful differences. These trials have contributed to our understanding of the optimal duration of therapy, 646 the role anthracyclines play, 647,648 and the benefits of treatment in both node-negative 640 and postmenopausal patients. At the present time, there is no woman with invasive breast cancer for whom we can say there is no benefit associated with adjuvant chemotherapy, but for many women the absolute benefit is exceedingly small. In such settings, the potential benefits of treatment need to be carefully balanced against the side effects and potential risks of treatment. Breast cancer is a heterogeneous malignancy with a highly variable natural history. While the extent of disease (or stage of disease) partially reflects the underlying biology of the cancer, a more comprehensive understanding of the molecular biology and genetics of breast cancer is needed. Ultimately, this understanding will allow us to tailor therapies for specific patient subgroups and to target therapies to different tissue types. Until we gain a better understanding of subgroup differences, we are forced to consider the risks and benefits of treatments across broad populations, as best exemplified by the Overview analysis. The results of 69 randomized trials involving approximately 30,000 women were included in the third and most recent analysis and publication of the Overview. As can be seen, there is a highly significant benefit for combination chemotherapy compared with no chemotherapy. For the population as a whole, polychemotherapy reduced the annual odds of recurrence by approximately 25% and the annual odds of death by approximately 15%. The reduction in recurrence as a result of chemotherapy was greatest during the first 5 years following diagnosis, although there was still a significant, although smaller, proportional reduction in recurrence as a result of chemotherapy even after 5 years. The effect of chemotherapy on survival was seen during the first 5 years and persisted to an equal or greater extent during the next 5 years. The fact that the survival curves continued to separate after 5 years is not surprising; recurrences of breast cancer during the first 5 years after a diagnosis may lead to death from breast cancer during the subsequent 5-year period. This finding underscores the importance of following women with early-stage breast cancer for an extended period of time to obtain a full picture of the effect of a therapy on long-term survival. The effect of adjuvant chemotherapy on women under age 50 is illustrated in Figure 37. Effect of polychemotherapy on recurrence and mortality in women less than 50 years of age. It is estimated from the Overview data that an average node-negative patient under age 50 would have an absolute improvement in survival at 10 years of 7% (an improvement from 71% to 78%). In contrast, the absolute improvement for a node-positive patient under age 50 is estimated to be 11% (an improvement from 42% to 53%). The Overview includes data on only approximately 600 women aged 70 or older, thus limiting any conclusions that can be drawn regarding this subgroup.
Sputum cytology and bronchoscopy may be helpful in documenting an occult bronchogenic adenocarcinoma. The Cancer Committee of the College of American Pathologists has established a checklist protocol for the examination of specimens from patients with malignant pleural mesothelioma. Metastatic adenocarcinoma with extensive pleural involvement may grossly resemble mesothelioma and has been called pseudomesothelioma. Synovial sarcoma and carcinosarcomas, which may also have mixed sarcomatous and epithelial components, usually present as a localized mass in the lung. Autopsy requires skilled performance and experienced interpretation to reliably exclude other occult primary carcinomas. Advanced malignant mesothelioma tends to form peripheral visceral masses mimicking primary carcinomas. Cytology In one study of 21 cases of epithelial malignant mesothelioma (15 pleural, 6 peritoneal) diagnosed by effusion cytology, 13 were of the cohesive cell type and 8 were of the noncohesive cell type. Because of its resemblance to florid reactive mesothelial hyperplasia and the general lack of awareness of the existence of the single-cell pattern of mesothelioma, the noncohesive cell type can often be missed. The median time from initial symptoms to the diagnosis of mesothelioma was 8 weeks (4 weeks for patients with positive or suspicious cytology results, and 12 weeks for those with negative cytology results). Cytogenetic analysis of pleural fluid had a sensitivity of 56% and was positive in one case in which results of cytologic examination were negative. Patients in whom the time from presentation to diagnosis was greater than 1 year all had negative cytologic results followed by long periods without further workup, despite a history of exposure to asbestos. Because the sensitivity of cytologic examination for mesothelioma is so low, patients in whom mesothelioma is suspected should undergo immediate pleural biopsy if the pleural fluid cytology result is negative. However, numerous distinct, uniformly small intracytoplasmic vacuoles, believed to represent intracellular fat and glycogen, were consistently present in metastatic lesions. Discrete nodules and plaques of firm, grayish tumor coalesce, eventually obliterating the parietal and visceral surfaces. A rind of up to 5 cm in thickness may encase and constrict the lung with only superficial invasion. The chest wall, pericardium, and diaphragm as well as the interlobar fissures are involved relatively early. Extensive sampling of biopsy, laparotomy, pleurectomy, or pneumonectomy specimens is required. A small piece should be fixed in glutaraldehyde for electron microscopy and the remainder promptly fixed in neutral buffered formalin. The sarcomatoid variant is composed of ovoid to spindle-shaped cells with cellularity and hyperchromatism similar to that of a fibrosarcoma. A biphasic pattern with mixed epithelial and sarcomatoid elements is virtually pathognomonic of malignant mesothelioma although extensive sampling may be required to demonstrate the minor component. Histochemical Methods Three methods are in common use to distinguish metastatic adenocarcinomas from epithelial mesotheliomas. Their presence is strong but not unequivocal evidence for a diagnosis of adenocarcinoma. Appropriate controls for diastase activity and to distinguish staining of vacuoles from stroma and other structures are essential. Mesotheliomas are usually negative but occasionally may stain strongly in some laboratories possibly due to fixation or technical conditions. Immunohistochemistry Immunoperoxidase stains using various antibodies may be effectively applied to paraffin-embedded tumor tissue. Monoclonal antibodies against keratin proteins are strongly reactive in mesothelioma with diffuse cytoplasmic staining, 72 and perinuclear accentuation with ring formation. Both epithelial and spindle-shaped tumor cells of mixed and sarcomatoid variants are often stained, reflecting transitional patterns of differentiation also observed on electron microscopy. Adenocarcinomas also stain positively, usually with localization to the periphery of the tumor cell.
One of the chief influences of diet is the production of fecal mutagens by certain diets. Changes in the fecal microflora indicate that changes in diet may alter mutagenic activity by altering extracellular superoxide formation. Changes in intestinal transit time owing to fiber intake affects the exposure of the mucosa to mutagens. In addition to mutagenic compounds such as fecapentaenes, the presence of other products of digestion such as 3-ketosteroids, which are products of cholesterol metabolism, may act as tumor promoters or initiators. Among the risk factors are the intake of red meats and the compounds that result from cooking meats at high temperatures. In a retrospective study of colorectal cancer patients, it was found that levels of the secondary bile acid deoxycholic acid were higher than normal and that the ratio between deoxycholic acid and cholic acid may be an indicator of risk. That folate is a potentially protective agent has been demonstrated also by other studies. Individuals with different forms of the 5,10-methylenetetrahydrofolate reductase gene may demonstrate different risks for colorectal cancer, which may account for differences in the effectiveness of folate supplementation on colorectal cancer risk. Epidemiologic studies show that higher rates of colon carcinoma are found in subjects with a higher stool pH. Numerous epidemiologic studies suggest that fiber exerts a protective effect, whereas other epidemiologic studies report no protective activity of fiber in relation to colorectal carcinoma. Cellulose and bran are specific examples of fibers that have demonstrated increased effectiveness. In addition, current and past smoking habits are independent factors that increase risk. The protective effect of hormonal replacement disappeared within 5 years after hormone use was discontinued. It involves identifying those persons at increased risk of death from colorectal cancer owing to the presence of premalignant lesions or early cancers. In nearly three-fourths of colorectal cancer cases, no predisposing factors will be identifiable. Fewer than 10% of cancers of the colorectum occur in people younger than 40 years. The increase in incidence occurs into the eighth decade of life, when a decline begins. Cumulative incidence of colorectal cancer by age in the general population (open circle), hereditary nonpolyposis colon cancer population (open square), and familial adenomatous polyposis population (closed circle). Its importance as a model for sporadic colorectal cancer development far outweighs its importance as a problem in public health. These syndromes have autosomal dominant inheritance with high but variable penetrance. It is important to realize that 10% to 20% of the cases are de novo mutations with no apparent family history. Since the introduction of genetic testing into the medical armamentarium, it is important that patients have access to appropriate genetic counseling and proper interpretation of test results. Its phenotypic features are early-onset colorectal cancer (mean age, 46 years), multiple (synchronous or metachronous) colorectal cancers (35%), and colorectal cancers usually (but not always) located in the proximal colon. Though the results of genetic testing depend on criteria used for instituting testing, the overall mutation detection rate appears to be greater than 50% in suspected cases. This less exclusionary set of criteria will reduce the number of families in which colorectal cancer is suspected but that fail to receive genetic counseling and mutation analysis. They prospectively screened tumor specimens from patients with colorectal adenocarcinomas for microsatellite instability. Sixteen percent of patients with replication errors had detectable germline mutations. All the patients in whom germline mutations were detected had a family history of colorectal cancer or were younger than 50 years. These guidelines are expected to apply to 15% to 20% of colorectal cancer patients in the United States. The polyps are nonneoplastic and have a characteristic branching muscular framework.
Diseases
Strategies for improving the outcome of patients with poor prognosis prostate cancers. Conservative management with symptomatic treatment and delayed hormonal manipulation is justified in men with locally advanced carcinoma of the prostate. Natural history of localised prostatic cancer managed by conservative therapy alone. Natural course of clinically localized prostate adenocarcinoma in men less than 70 years old. Deferred treatment of clinically localized low-grade prostate cancer: actual 10-year and projected 15-year follow-up of the Karolinska series. Fifteen-year survival in prostate cancer: a prospective population-based study in Sweden. Deferred treatment of locally advanced nonmetastatic prostate cancer: a long-term followup. Long-term survival among men with conservatively treated localized prostate cancer. Long-term survival and mortality in prostate cancer treated with noncurative intent. Prostate cancer mortality in patients surviving more than 10 years after diagnosis. Prostate cancer mortality in northern Sweden, with special reference to tumor grade and patient age. Long-term outcome of conservative therapy in men presenting with voiding symptoms and prostate cancer. Mortality of patients with clinically localized prostate cancer treated with observation for 10 years or longer: a population based registry study. Deferred treatment of low grade stage T3 prostate cancer without distant metastases. Competing risk analysis of men aged 55 to 74 years at diagnosis managed conservatively for clinically localized prostate cancer. Pelvic lymphadenectomy can be omitted in selected patients with carcinoma of the prostate: development of a system of patient selection. Utility of preoperative serum prostate-specific antigen concentration and biopsy Gleason score in predicting risk of pelvic lymph node metastases in prostate cancer. Early experience with intraoperative cavernous nerve stimulation with penile tumescence monitoring to improve nerve sparing during radical prostatectomy. The incidence and significance of detectable levels of serum prostate specific antigen after radical prostatectomy. Long-term (15 years) results after radical prostatectomy for clinically localized (stage T2c or lower) prostate cancer. An algorithm for predicting nonorgan confined prostate cancer using the results obtained from sextant core biopsies with prostate specific antigen level. Delayed/salvage radiation therapy in patients with elevated prostate specific antigen levels after radical prostatectomy. Effect of combined transient androgen deprivation and irradiation following radical prostatectomy for prostatic cancer. Salvage radiotherapy for biochemical and clinical failures following radical prostatectomy. The value of serum prostate specific antigen determinations before and after radical prostatectomy. Prostate specific antigen levels after radical prostatectomy in patients with organ confined and locally extensive prostate cancer. Undetectable serum prostate-specific antigen associated with metastatic prostate cancer: a case report and review of the literature. Pathological features and prognostic significance of prostate cancer in the apical section determined by whole mount histology.
Potentiation of 1,2-dimethylhydrazine-induced anal carcinoma by epidermal growth factor in mice. The pathology and results of treatment of squamous cell carcinoma of the anal canal and anal margin. A comparative study of melanoma and epidermoid carcinoma of the anal canal: a review of 20 melanomas and 29 epidermoid carcinomas. The association of squamous cell cancer with anal manifestations of lymphogranuloma venerum. Transanorectal ultrasonography in anal carcinoma: a prospective study of 21 patients. Conservative management by irradiation of epidermoid cancers of the anal canal: prognostic factors of tumor control and complications. Treatment of anal canal carcinoma with high dose radiation therapy and concomitant fluorouracil-cisplatinum. Primary chemoradiation therapy with fluorouracil and cisplatin for cancer of the anus: results in 35 consecutive patients. Salvage abdominoperineal resection following combined chemotherapy and radiotherapy for epidermoid carcinoma of the anus. Epidermoid anal cancer: treatment by radiation alone or by radiation and 5-fluorouracil with and without mitomycin-C. The impact of treatment factors on local control in T2-T3 anal carcinomas treated by radiotherapy with or without chemotherapy. Management of anal epidermoid carcinoma: an evaluation of treatment results in two population-based series. Epidermoid carcinoma of the anal canal treatment results and prognostic variables in a series of 242 cases. Resultats du traitement de 286 cas de cancers epidermoides du canal anal dont 236 par irradiation a visee conservatrice. Prognostic factors in anal squamous carcinoma: a multivariate analysis of clinical, pathological, and flow cytometric parameters in 235 cases. Prognostic role of p53 protein expression in epidermoid carcinoma of the anal canal. Respective roles of radiotherapy and surgery in the management of epidermoid carcinoma of the anal margin. Results of surgical treatment of squamous cell carcinoma of the anal canal and anal margin seen at St. Laser ablation of squamous cell carcinoma in situ of the anal canal: a case report. Depth of invasion, location, and size of cancer of the anus dictate operative treatment. Conservative treatment by irradiation of epidermoid carcinomas of the anal margin. Interstitial curietherapy in the conservative treatment of anal and rectal cancers. Treatment of squamous cell anal canal carcinoma with pulsed dose rate brachytherapy. Interstitial iridium-192 implantation combined with external radiotherapy in anal cancer: ten years experience. Impact of clinical and therapeutic factors on major late complications after radiotherapy with or without concomitant chemotherapy for anal carcinoma. New method of radiotherapy for anal cancer with three-dimensional tumor reconstruction based on endoanal ultrasound and ultrasound-guided afterloading therapy. Pre-operative chemotherapy and radiation therapy in the management of anal epidermoid carcinoma. Definitive irradiation and chemotherapy for radiosensitization in management of anal carcinoma: interim report on radiation therapy oncology group study no. Feasibility and outcome of radical radiotherapy with or without concomitant chemotherapy. Our experience of conservative treatment of anal canal carcinoma combining external irradiation and interstitial implants: 32 cases treated between 1973 and 1982.
Lipiodol-epirubicin gave a higher tumor response rate as compared with epirubicin alone (42% vs. Larger, randomized trials have been unable to substantiate a survival benefit for such Lipiodol chemoembolizations, however. A randomized study comparing treatment using Lipiodol plus Adriamycin to Lipiodol alone showed a trend toward a better response at 1 and 2 years with the combination of Lipiodol and Adriamycin, but the difference was not statistically significant. Because of the small size of individual studies, metaanalyses of the published randomized studies have been performed 146 but have failed to show any clear benefit of transarterial chemoembolization over no treatment. At times, the response can be very dramatic, resulting in impressive relief of symptoms. Hence, these treatments may be useful in a patient with ruptured tumors or tumors that are symptomatic in pain or paraneoplastic syndromes. In addition, it is our bias (though not yet supported by randomized trials) that, for the subset of patients with good liver function, tumors of less than 10 cm in diameter, less than 50% liver replacement by tumors, and no portal vein thrombus, selective embolization may be beneficial. It is in this favorable subset of patients that future clinical trials should be directed, examining the utility of embolization. We believe that current data do not support the use of chemoembolization or Lipiodol mixtures but rather indicate that these complex mixtures may merely add cost and complications without improving efficacy. At present, we prefer to use simple particle embolization for treatment of symptomatic or favorable tumors. It is likely that effective palliative therapy will be a combination of local therapy by embolization and an as-yet unidentified systemic treatment. Radiotherapy Initial attempts to use whole liver radiation in the treatment of primary hepatobiliary cancer were unsuccessful. The most important reason for this lack of success is the low tolerance of the liver to whole organ radiation. Attempts have been made to increase the effectiveness of whole liver irradiation in the treatment of patients with unresectable hepatoma by the addition of intravenous chemotherapy 211,212 and 131I antiferritin monoclonal antibody therapy. The finding that hepatic arterial cisplatin and radiation can produce an objective response rate of 43% and a median survival of 7. At least four techniques have been assessed: 90Y microspheres, 131I-labeled ethiodized oil, and external-beam radiotherapy with either protons or photons. When bombarded with neutrons, 89Y is converted to 90Y, a pure beta emitter with a half-life of 64. The microspheres have been infused into the hepatic artery as a form of regional therapy for well-vascularized tumors, producing objective response rates ranging from 0% to 25% 109,216,117 and 218 (for review, see Ho et al. Note that 90Y doses (50 to 150 Gy) cannot be compared directly to the more familiar external-beam doses, as the former are calculated by assuming full decay with all radiation homogeneously deposited within the liver. A better understanding of the dosimetry of this technique 220 as well as of the technical factors (such as pulmonary shunting, which can lead to radiation pneumonitis, 221 or variant arterial supply to the stomach, which can produce gastric ulcers) is required before the application of microspheres can become routine. Another method of delivering focal liver irradiation involves hepatic arterial administration of 131I ethiodized oil. There was no difference in overall survival between the two groups (median survival, approximately 40 weeks), but the toxicity of the ethiodized oil arm was significantly less. In the latter study, 27 patients were randomized to receive either 60 mCi of 131I-labeled ethiodized oil or control treatment (such as tamoxifen). The ethiodized oil group showed a statistically significantly greater median survival (approximately 6 months as compared to 2 months). Furthermore, as is the case for 90Y, little is known about the tumor and normal tissue dosimetry. However, standard photon techniques often require the treatment of large volumes of normal liver. Patients who can receive more than 70 Gy have a median survival in excess of 17 months, which approaches that achieved by surgical resection. In a multivariate analysis, dose is a prognostic factor independent of tumor size. A number of theoretic models (all of which require knowledge of the 3D dose distribution) have been proposed to estimate the volume dependence of normal tissue tolerance.
Eighty-five percent of patients had postoperative complications, and 21 of 33 patients (73%) required further surgery. The most common complications were joint instability (55%), degenerative joint disease (44%), nonunion (36%), allograft fracture (28%), and infection (17%). A steady decline in actuarial survivorship of the reconstruction was noted over time: 83. Allograft replacement remains popular at some institutions but is reserved for low-grade tumors that do not require chemotherapy. The use of allografts has become less common with the development of reliable prosthetic replacements, especially the modular replacement systems. Prosthesis Survival and Complications Prosthetic replacement is commonly used for reconstruction after resection of the proximal humerus, proximal femur, distal femur (. Several studies have evaluated the long-term results, prosthetic survivorship, and complications associated with prosthetic replacement. The authors thought that the most serious problems resulting from a complication were those that required the delay of chemotherapy or deviation from the recommended dose, either of which could jeopardize survival. Campanna and colleagues265 from the Rizzoli Institute reported on 95 distal femoral resections performed between 1983 and 1989 (average follow-up, 51 months). The most common complication was failure of the polyethylene bushings used with the knee component, which occurred at an average of 5. Mechanical stem breakage was rare (6%) and was associated with two factors-the use of a narrow stem and extensive quadriceps excision. The incidence of infection correlated with the extent of soft tissue resection of the quadriceps. Malawer and Chou262 evaluated the prosthetic survivorship of large-segment prostheses in 89 patients with high-grade bone sarcomas. The 5- and 10-year prosthetic survival rates (no need for revision or amputation) were 83% and 67%, respectively. The authors of this study suggested that infection was related to periods of bacteremia and neutropenia associated with postoperative chemotherapy and to episodes of line sepsis. Kaplan-Meier survival analysis was performed for all implants and for each site of reconstruction. The authors reported no mechanical failures of the stem, body, or taper components. The infection rate was 8% (four in distal femurs, three in proximal tibias, and one in proximal humerus), leading to six amputations and one prosthetic removal. The estimates of 10-year survival for the distal femur, proximal humerus, proximal femur, and proximal tibia were 90%, 98%, 100%, and 78%, respectively. Today, modular prostheses are forged by several manufacturers and are the standard prostheses used for most limb-sparing procedures. Kaplan-Meier curve showing the survival of prosthetic replacements according to anatomic site in 100 patients treated by limb-sparing surgery for high-grade bone sarcomas. The anatomic site was the most significant predictor of survival of the prosthesis. Distal Femur, distal or mid-part of the femur; Prox Humerus, proximal part of the humerus; Prox Femur, proximal portion of the femur; Prox Tibia, proximal portion of the tibia. The early causes of prosthetic failure were postoperative infection, secondary infection due to transient bacteremia during postoperative chemotherapy, and local recurrence. Long-term survival of the prosthesis depends on the mechanical properties of theprosthesis and on the host response to the polyethylene, methylmethacrylate, and metallic components. The most common reasons for a revision were polyethylene wear (nine cases) and aseptic loosening (eight cases). The follow-up after the last revision ranged from 6 months to 12 years, with a median of 3 years. All patients retained their extremity, and approximately 75% incurred no functional loss after prosthetic revision.
References:
