Prognostic factors in osteosarcoma: a critical review

PURPOSE

The purpose of this critical appraisal was to determine the prognostic factors that influence survival in patients with nonmetastatic, high-grade osteosarcoma of the extremities.

DESIGN

A computerized literature search of reports published from January 1973 to March 1992 was conducted to determine those eligible for inclusion in the review. Reports were reviewed blindly by two of the authors; inclusion and scoring were determined according to preestablished criteria.

RESULTS

Eight reports were included in the appraisal. The prognostic variables evaluated were age, sex, anatomic tumor location, tumor size, and tumor necrosis. Tumor size and necrosis following preoperative chemotherapy were significant prognostic variables in relation to survival in univariate analysis. However, only tumor necrosis maintained its significance in multivariate modeling.

CONCLUSION

The most important prognostic variable for patients with osteosarcoma of the extremity was tumor necrosis evident following preoperative chemotherapy. There is no consensus as to any prognostic variable that might be used to stratify patients before the onset of therapy.

The restaging of responding patients with limited small cell lung cancer. Is it really useful?

A retrospective review of data on patients entered on two limited small cell lung cancer studies of the National Cancer Institute of Canada (BR.3 and BR.6) was undertaken to determine the value of restaging and rebronchoscopy in responding patients. An economic evaluation was also done. Repeat scans (brain, liver) and bronchoscopy were carried out in 190 patients and 5 (2.6 percent) were positive, despite other evidence suggesting response. One hundred thirty-nine of 324 patients who achieved complete response on the two trials underwent rebronchoscopy. Among these, 122 (87.7 percent) were negative and eight (5.8 percent) were inconclusive. Nine (6.5 percent) were positive despite other evidence suggesting the patient had achieved a complete response. A small group of nine patients with positive rebronchoscopy survived for a shorter time than the group with negative or inconclusive rebronchoscopies. The survival difference was only statistically significant when analyzed using the log rank test, but it was not significant when analyzed by the Wilcoxon test. The economic analysis showed that it costs $11,333 per patient reclassified when scans were redone in these patients. The cost could even have been higher had we used present-day scanning techniques (computed tomography and magnetic resonance imaging), although they might be slightly more sensitive. The cost of rebronchoscopy per patient reclassified was $14,960. Therefore, we recommend that restaging (scans or rebronchoscopy) not be done in responding patients with limited small cell lung cancer, thus potentially saving health care dollars as well as reducing patient inconvenience with no detrimental effect on survival.

Alcohol and breast cancer risk--putting the current controversy into perspective

The potential association of alcohol intake with breast cancer risk is currently being debated in the literature and a clear consensus of opinion has not emerged. Clarification of the issues surrounding this controversy would be helpful in developing recommendations for the general public regarding alcohol use. A review of the available evidence regarding the association of alcohol with breast cancer is presented followed by an application of the Bradford Hill criteria for causal inference to this data to examine the existence and nature of the association of alcohol with breast cancer risk. Results of published studies demonstrated a weak association of alcohol with breast cancer risk that was consistent only for relatively high levels of intake (more than 1 or 2 drinks daily). Increasing daily intake was associated with increased risk, but the association was not linear. Criteria relating to temporality and analogy to other causal associations were satisfied while inconsistent evidence was available for those relating to epidemiologic and biologic sense. The criterion for specificity was not satisfied and no experimental evidence was available. It is concluded that insufficient evidence exists to support a causal association of alcohol consumption with breast cancer risk. Further research is recommended to resolve conflicting evidence and to provide additional evidence where needed. In the meantime, recommendations that women should reduce their consumption of alcohol beyond existing guidelines to modify breast cancer risk are probably premature.

Body size and breast cancer prognosis: a critical review of the evidence

There is currently controversy about the effect of body size on the prognosis of patients with breast cancer. In order to clarify the prognostic importance of body size, and to determine whether the effect varies across subgroups of patients, a critical appraisal of the published literature was undertaken. Thirteen cohort studies and one case-control study were identified that examined the prognostic effect of body size. Methodologic standards were developed that reflected those features of study design considered most important in studies of prognosis in breast cancer, and were independently applied to each report by each of the authors. When the effects of methodologic differences among the studies were controlled, a modest prognostic effect of body size was identified. This effect appeared to be greatest in postmenopausal women, in those with little or no involvement of axillary nodes, and to be independent of other prognostic factors. Additional investigation is recommended to determine the prognostic effects of body size in postmenopausal women with axillary node negative breast cancer and in women receiving systemic adjuvant therapy, and to determine the pathophysiological basis for these effects. Intervention studies to determine the effects of altering body size may also be indicated.

Counting the costs of chemotherapy in a National Cancer Institute of Canada randomized trial in nonsmall-cell lung cancer

An economic evaluation was undertaken of a previously reported National Cancer Institute of Canada (NCIC) trial of chemotherapy in advanced nonsmall-cell lung cancer (NSCLC). That trial had demonstrated a survival benefit associated with the use of either vindesine and cisplatin (VP) or cyclosphosphamide, doxorubicin, and cisplatin (CAP) in relation to best supportive care (BSC). The economic technique used in this evaluation was cost-effectiveness analysis (CEA). All costs were determined from the viewpoint of two provincial health care plans. When compared with BSC, the survival benefit of 8 weeks in favor of patients receiving CAP chemotherapy was associated with an economic saving of $949.49 (in 1984 Canadian dollars). This translated into a savings of $6,171.69 per year of life gained. The mean survival benefit of 12.8 weeks that was obtained with VP chemotherapy compared with BSC was associated with an increased cost of $3,637.60 per patient, or $14,777.75 per year of life gained. The economic evaluation demonstrated that the majority of costs on each of the three treatment arms was related to hospitalization and not to the use of chemotherapy agents. These results compare favorably with estimates of cost-effectiveness (CE) of commonly used treatments for other diseases and demonstrate that a policy of supportive care is associated with costs that may exceed those of active treatment. It is concluded that economic factors should not adversely affect decisions regarding the use of chemotherapy in advanced NSCLC.

Mechanisms of abnormal endothelium-dependent vascular relaxation in atherosclerosis: implications for altered autocrine and paracrine functions of EDRF

The present studies were performed to determine if abnormal endothelium-dependent vascular relaxation in atherosclerosis is due to decreased production or release of endothelium-derived relaxing factor (EDRF) by atherosclerotic rabbit vessels or if atherosclerotic vessels are less sensitive to the relaxing effects of EDRF. EDRF release was quantified using two approaches, by the response of bioassay detector vessels and also by the activation of guanylate cyclase within cultured endothelial cells. Using these assays, atherosclerotic vessels were found to release significantly less EDRF than normal vessels in response to both receptor- and nonreceptor-mediated stimuli. Relaxations of normal and atherosclerotic vessels to luminally applied EDRF (derived from normal rabbit aortas stimulated by the calcium ionophore, A23187) and nitric oxide, a putative EDRF, were also studied. Atherosclerotic vessels were more sensitive to EDRF than normal vessels, and equally sensitive to nitric oxide. Additional studies performed in organ chambers failed to demonstrate augmented constriction of atherosclerotic vessels in response to acetylcholine in the presence or absence of methylene blue or LY83583, compounds which inhibit the effect of EDRF. We conclude that decreased EDRF release is the principal underlying mechanism responsible for abnormal endothelium-dependent vascular relaxation in atherosclerosis.

Cost-effectiveness of cancer chemotherapy: an economic evaluation of a randomized trial in small-cell lung cancer

An economic evaluation of a randomized trial of cyclophosphamide, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and vincristine alone or alternating with etoposide (VP-16) and cisplatin in extensive small-cell lung cancer (SCLC) was undertaken. A survival benefit of 1.6 months in favor of alternating chemotherapy was associated with an additional cost of $450 (1984 Canadian dollars) per patient. This translated to a cost of $3,370 per year of life gained. Sensitivity analyses demonstrated that the cost-effectiveness (CEA) of alternating chemotherapy was greatest when treatment was given on an outpatient basis. The results of the evaluation were sensitive to hospitalization rates, but even the most unfavorable analyses revealed the CEA of alternating chemotherapy to be comparable to that of treatments of common nonmalignant diseases. It is concluded that the CEA of alternating chemotherapy for SCLC was favorable when compared with accepted treatments for nonmalignant diseases. The survival benefit seen with alternating chemotherapy was felt to be clinically significant and alternating chemotherapy is recommended as routine therapy for extensive SCLC.

Cyclical mastopathy: a critical review of therapy

Because of a recently completed trial which demonstrated that dietary fat reduction improved the symptoms of cyclical mastopathy, we have carried out a critical review of other studies of treatment for this disorder to determine what, if any, mechanisms of action were shared by effective treatments. Therapies were classified as 'definitely effective' if their effectiveness was demonstrated in at least one randomized placebo-controlled study of women with cyclical mastopathy, 'probably effective' if their effectiveness in relieving breast symptoms was demonstrated in at least one study in women with premenstrual syndrome, and 'probably not effective' if they had not been shown to improve breast symptoms in at least two studies in women with premenstrual syndrome. Bromocriptine, danazol, evening primrose oil, tamoxifen and reduction of dietary fat intake were classified as definitely effective and norethisterone and Bellergal as probably effective. Several therapeutic manoeuvres, including reduction of methylxanthine ingestion and the administration of vitamin E or diuretics, have not been adequately evaluated in women with cyclical breast symptoms. A review of the published reports of the physiological effects of therapies that were definitely or probably effective revealed that these agents acted either to alter serum prolactin levels or lipid metabolism, or both. As evidence exists that prolactin influences lipid metabolism it is postulated that cyclical mastopathy may be a disorder of lipid metabolism.

Weight gain in women with localized breast cancer--a descriptive study

A retrospective study was undertaken of weight gain during the first year after diagnosis of breast cancer in three groups of women with localized disease. Group I consisted of 307 women with clinical or pathological node-negative breast cancer and Group II of 139 women with clinical or pathological node-positive breast cancer. Neither of these groups received systemic adjuvant therapy. Group III consisted of 191 women with pathological node-positive breast cancer who received adjuvant cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) (Group IIIA) or CMF plus prednisone (7.5 mg per day) and ovarian ablation (Group IIIB). In the absence of systemic therapy, weight gain was greater in those with involved nodes than in those with uninvolved nodes (p = 0.001). When women with involved nodes were studied, those who received prednisone and ovarian ablation in addition to CMF gained more weight than those who received CMF alone (p less than 0.0001). The use of CMF alone did not significantly affect weight gain. Neither initial weight nor weight gain after diagnosis affected prognosis. It was concluded that the observed weight gain was not due to the use of adjuvant CMF and did not affect prognosis. Further investigation was recommended to replicate the above findings and to determine the cause of weight gain after diagnosis in women with localized breast cancer.

Critical appraisal of the evidence that dietary fat intake is related to breast cancer risk in humans

A critical appraisal was undertaken of the evidence that dietary fat intake is related to breast cancer risk by application of the criteria for causal inference proposed by Bradford Hill to the published evidence that relates dietary fat to breast cancer risk in humans. These criteria concern the consistency, strength, and temporal relationships of possible causative associations and also require the existence of a biologic gradient and examine the extent to which the proposed causal association is in keeping with other biological and epidemiological knowledge. The published reports were inconsistent in their ability to detect a significant association between dietary fat and breast cancer risk, correlation studies that examined the effect of fat over large ranges being largely positive, and studies with stronger designs (case-control, cohort) that examined fat intake over much smaller ranges being largely negative. It was postulated that methodologic limitations associated with the design of the latter studies, in particular the small ranges of fat intake examined and inaccuracies in the measurement of fat intake, may have obscured any relationships between dietary fat and breast cancer that did exist. The remaining criteria, with the exception of temporality and epidemiological coherence, were not satisfied. Insufficient evidence existed to conclude a causal association existed between dietary fat and breast cancer risk in humans. A need for further study was identified in several areas, and it was concluded that intervention studies that examined the effect of fat over large ranges were most likely to yield the information required to determine whether dietary fat intake was causally related to breast cancer risk.

Phencyclidine: effects of chronic administration in the female mouse on gestation, maternal behavior, and the neonates

Phencyclidine (PCP) (5 mg/kg) was administered daily throughout gestation and pups were crossfostered or fostered after birth. Prenatal weight gain, lenght of gestation, length of parturition, and the size and birth weight of the litters were not affected by PCP administration. No congenital malformations were evident and the mother's health during chronic exposure remained normal. Physical development of the pups (indicated by neonatal weight gain, pinna opening, and eye opening), and neurological development (indicated by the maturity of four reflex actions) were normal for the PCP pups. Behaviorally, PCP pups were slightly more active in the open field at 60 days. Maternal behavior was not influenced by drug treatment, but was affected by the fostering procedures.