Evolution and replacement of Candida albicans strains during recurrent vaginitis demonstrated by DNA fingerprinting

Southern blot hybridization with the Ca3 probe and the C fragment of the Ca3 probe was used to assess the genetic relatedness of Candida albicans strains from one patient with recurrent C. albicans infection in whom the same strain was maintained, one patient in whom the infecting strain was replaced, and their male sexual partners. In the patient in whom the infecting strain was maintained, the infecting strain exhibited a minor genetic change in each successive episode of Candida vaginitis. These genetic changes occurred in the C-fragment bands of the Ca3 hybridization pattern. In the patient in whom the infecting strain was replaced by another infecting strain, a transition infection involved a genetically mixed infecting population, and the replacement strain appeared to have originated from the oral cavity of the male partner. The results demonstrate that the infecting strains of recurrent Candida vaginitis are not genetically stable, that drug treatment can result in the selection of variants of the previously infecting strain or replacement by a genetically unrelated strain, and that the male partner can be the source of a replacement strain.

Evaluation of a rapid test to detect Streptococcus group A

Rapid tests for the detection of group A beta-hemolytic streptococcus (GABHS) directly from a throat swab have become very popular. Previous studies have reported an antigen test sensitivity of 55-95% and a specificity of 88-100%. The present study evaluates the reliability of one rapid test in detecting GABHS (PathoDx). A total of 164 throat swab specimens was taken. GABHS was isolated on the culture in 37 (22.5%), and the rapid test was positive in 60 (36.6%). The sensitivity of the rapid test was 86.5% and the specificity 80%. Of the 60 positive rapid test results, 28 (47%) were false positive and the positive predicted value was 53%. We conclude that results obtained using rapid test kits should be compared to throat cultures in order to determine the reliability of such kits in specific clinical settings.

Twice-daily fractionation of external irradiation with brachytherapy in bulky carcinoma of the cervix. Phase I/II study of the Radiation Therapy Oncology Group 88-05

BACKGROUND

Hyperfractionated radiation therapy (HFX), which may permit higher total doses of radiation therapy without increased toxic effects to normal tissues, has been used with pelvic tumors, but its combination with brachytherapy has not been well studied.

METHODS

A prospective Phase I/II trial was designed to study HFX with brachytherapy in patients with bulky Stage IB and IIA, IIB, III, and IVA carcinomas of the cervix. HFX doses of 1.2 Gy were administered to the whole pelvis twice daily at 4-6 hour intervals, 5 days per week; the total dose to the whole pelvis was 24-48 Gy. External pelvic irradiation was followed by one or two intracavitary applications to deliver the total minimum dose of 85 Gy at point A and 65 Gy to the lateral pelvic nodes.

RESULTS

Eighty-one patients were enrolled in this protocol; 14% had Stage IB, 43% stage II, 38% stage III, and 4% stage IVA carcinomas. Seventy-one patients were evaluable for HFX and brachytherapy; 38 patients received one intracavitary application, and 33 received two applications. Four patients had Grade 3 acute reactions. The cumulative rates of Grade 3-4 late toxicities were 1.9% at 1 year, and 6.3% at 2 and 3 years. Of 80 patients evaluated for response, 80% had complete disappearance of disease. Comparisons with historical rates of late toxicity with standard fractionation (STD) revealed similar results in spite of higher total doses with HFX. Comparisons between historical STD and HFX also revealed equivalent rates of pelvic tumor control, Grade 3-4 toxicity, and survival at 3 years.

CONCLUSIONS

Results suggest that combined with brachytherapy, HFX at total parametrial doses 10% above those used with STD was tolerated and at least as effective as STD. Further study with higher doses and extended fields is indicated. Comparisons of long term (5-plus years) survival and late-effects rates with STD versus HFX are planned.

"Compensated" split-course versus continuous radiation therapy of carcinoma of the tonsillar fossa. Final results of a prospective randomized clinical trial of the Radiation Therapy Oncology Group

The Radiation Therapy Oncology Group conducted a prospective comparison of a compensated split course radiotherapy technique (300 cGy x 10, 3 weeks rest, 300 cGy x 10), versus continuous radiotherapy (200-220 cGy up to 6000-6600 cGy), in 137 evaluable patients. The complete response (CR) was 57% in 63 patients, treated with the split-technique vs 61% in 74 patients submitted to continuous course radiotherapy. The completion of therapy as planned was better in the split-technique, but acute and late tissue reactions were the same. Locoregional control of tumor at 5 years was 25% for split and 28% for continuous therapy. At 7 years this was 25% and 24%, respectively. Absolute survival in the split-course patients tended to be lower than in the continuous group, but when the sample of patients was enlarged by the addition of cases from similar trials of nasopharynx and base of tongue lesions, the survival difference was eliminated. On the basis of the results of this study we conclude that the stated compensated split-course technique gives equal clinical results as conventional continuous therapy, with the advantage of requiring fewer radiation fractions, and less burden on the patient and therapy facilities.

Poor survival of black patients in carcinoma of the endometrium

PURPOSE

To compare the prognostic factors and survivals of black and white patients with endometrial carcinoma.

METHODS AND MATERIALS

A retrospective study was undertaken of a total of 290 patients with endometrial carcinoma who were treated similarly at the Health Science Center at Brooklyn and Kings County Hospital Center from 1975 and 1990. One hundred and thirty-six of 290 (47.2%) were black and 135/290 (46.9%) were white. Well-known prognostic factors affecting endometrial carcinoma were studied in black and white group of patients. Their overall survival and comparison of survival in each prognostic group were also estimated using multi-variate analysis.

RESULTS

Fifty-four percent of white patients had Stage I disease, compared to 45.9% in black patients. In Stage II, 51.6% were white and 48.4% were black, and in Stage III, 88.89% were black and 11.1% were white patients (p = 0.034). Fifty six percent Grade 1 patients were white and 44% were black. In Grade 2, 53.3% were white and 46.7% were black and in Grade 3 disease, 70.5% were black and 29.5% were white (p = 0.008). Up to the inner third of myometrial invasion had occurred in 60.6% of white patients and 39.4% in black patients. The middle third of the myometrium was invaded in 60.7% of white patients, and 39.3% of black patients. Thirty-seven percent of outer third of myometrial invasion was found in white patients and 63% in black patients (p = 0.038). Seventy-two percent of positive lymph nodes were found in black patients and 28.0% in white patients (p = 0.01). Sixty-one percent of patients with positive peritoneal cytology were black as compared to 38.7% in white patients (p = 0.017). The overall ten-year corrected survival for white and black patients was 72% and 40%, respectively (p = 0.0003). Survivals comparisons, when stratified by race and each prognostic group, showed statistically significant overall survival differences in favor of white patients.

CONCLUSION

Black patients with endometrial carcinoma have poor survival. Low socio-economic status (SES) would not explain these findings. More research is required to determine the cause of poor survival in black patients with endometrial carcinoma.

Accelerated hyperfractionated hepatic irradiation in the management of patients with liver metastases: results of the RTOG dose escalating protocol

PURPOSE

This study was prepared to address two objectives: (a) to determine whether progressively higher total doses of hepatic irradiation can prolong survival in a selected population of patients with liver metastases; (b) to refine existing concepts of liver tolerance for fractionated external radiation employing a fraction size which might be appropriate in clinical protocols evaluating elective or adjuvant radiation of the liver.

METHODS AND MATERIALS

One hundred seventy-three analyzable patients with computed tomography measurable liver metastases from primary cancers of the gastrointestinal tract were entered on a dose escalating protocol of twice daily hepatic irradiation employing fractions of 1.5 Gy separated by 4 hr or longer. Sequential groups of patients received 27 Gy, 30 Gy, and 33 Gy to the entire liver and were monitored for acute and late toxicities, survival, and cause of death. Dose escalation was implemented following survival of 10 patients at each dose level for a period of 6 months or longer without clinical or biochemical evidence of radiation hepatitis.

RESULTS

The use of progressively larger total doses of radiation did not prolong median survival or decrease the frequency with which liver metastases were the cause of death. None of 122 patients entered at the 27 Gy and 30 Gy dose levels revealed clinical or biochemical evidence of radiation induced liver injury. Five of 51 patients entered at the 33 Gy level revealed clinical or biochemical evidence of late liver injury with an actuarial risk of severe (Grade 3) radiation hepatitis of 10.0% (+/- 7.3% S.E.) at 6 months, resulting in closure of the study to patient entry.

CONCLUSION

The study design could not credibly establish a safe dose for hepatic irradiation, however, it did succeed in determining that 33 Gy in fractions of 1.5 Gy is unsafe, carrying a substantial risk of delayed radiation injury. The absence of apparent late liver injury at the 27 Gy and 30 Gy dose levels suggests that a prior clinical trial of adjuvant hepatic irradiation in patients with resected colon cancer may have employed an insufficient radiation dose (21 Gy) to fully test the question.

Phase I/II trial of accelerated fractionation in brain metastases RTOG 85-28

PURPOSE

Radiation Therapy Oncology Group 85-28 represents a Phase I/II trial of accelerated fractionation in patients with brain metastases.

METHODS AND MATERIALS

Patients entered had controlled or absent primary with metastases other than brain which were stable or only brain metastases with the primary uncontrolled. Karnosfky status was required to be greater than 60. Patients received 1.6 Gy twice daily separated by 4-8 hr delivered 5 days a week. The entire brain was treated to 32.0 Gy and the boost dose escalated from 16.0 Gy to 22.40 Gy and subsequently 32.00 Gy and 42.40 Gy.

RESULTS

We observed no undue toxicity with escalating dose of irradiation. An incremental, although not statistically significant improvement in survival was noted with escalating doses. Median survival ranged from 4.2 months to 6.4 months with escalating dose of irradiation. Median survival also increased in patients with controlled primary tumors, non-lung primaries and solitary metastasis.

CONCLUSION

The incremental improvement in survival in patients with good prognostic factors appeared encouraging. The Radiation Therapy Oncology Group will test the 54.4 Gy study against 30 Gy in 2 weeks in a Phase III trial based on the results of this trial.

Influence of location and extent of surgical resection on survival of patients with glioblastoma multiforme: results of three consecutive Radiation Therapy Oncology Group (RTOG) clinical trials

PURPOSE

The influence of tumor site, size, and extent of surgery on the survival of patients with glioblastoma multiforme treated on three consecutive prospectively randomized Radiation Therapy Oncology Group trials employing surgery and irradiation plus or minus chemotherapy was studied.

METHODS AND MATERIALS

Six hundred forty-five patients with a diagnosis of glioblastoma multiforme on central pathological review were analyzed for survival with respect to known prognostic factors, that is, age and Karnofsky Performance Status, as well as extent of surgery, site, and size. Surgical treatment consisted of biopsy only in 17%, partial resection in 64%, and total resection in 19%. Tumors were located in frontal lobe in 43%, temporal lobe in 28%, and parietal lobe in 25%. Maximum tumor diameter as determined on computed tomography or magnetic resonance imaging scans was less than 5 cm for 38%, between 5-10 cm for 56% and greater than 10 cm for 6% of patients. The extent of surgical therapy was the same for tumors greater than 5 or greater than 10 cm, whereas total resection was more often performed for tumors less than 5 cm. The extent of surgery did not appear to vary with age or site.

RESULTS

Patients undergoing total resection had a median survival of 11.3 months compared to 6.6 months for patients with a biopsy only. A significant difference in median survival was also found for partial resection versus biopsy only treatment (10.4 vs. 6.6 months). There was no difference in survival for the different tumor sizes. Patients with frontal lobe tumors survived longer than those with temporal or parietal lobe lesions (11.4 months, 9.1 months, and 9.6 months, respectively) (p = 0.01). A Cox multivariate model confirmed a significant correlation of age, Karnofsky Performance Status, extent of surgery, and primary site with survival. The best survival rates occurred in patients who had at least three of the following features: < 40 years of age, high Karnofsky Performance Status, frontal tumors, and total resection (17 months median).

CONCLUSION

We conclude that biopsy only yields inferior survival to more extensive surgery for patients with glioblastoma multiforme treated with surgery and radiation therapy.

Recursive partitioning analysis of prognostic factors in three Radiation Therapy Oncology Group malignant glioma trials

BACKGROUND

Despite notable technical advances in therapy for malignant gliomas during the past decade, improved patient survival has not been clearly documented, suggesting that pretreatment prognostic factors influence outcome more than minor modifications in therapy. Age, performance status, and tumor histopathology have been identified as the pretreatment variables most predictive of survival outcome. However, an analysis of the association of survival with both pretreatment characteristics and treatment-related variables is necessary to assure reliable evaluation of new approaches for treatment of malignant glioma.

PURPOSE

This study of malignant glioma patients used a non-parametric statistical technique to examine the associations of both pretreatment patient and tumor characteristics and treatment-related variables with survival duration. This technique was used to identify subgroups with survival rates sufficiently different to create improvements in the design and stratification of clinical trials.

METHODS

We used a recursive partitioning technique to analyze survival in 1578 patients entered in three Radiation Therapy Oncology Group malignant glioma trials from 1974 to 1989 that used several radiation therapy (RT) regimens with and without chemotherapy or a radiation sensitizer. This approach creates a regression tree according to prognostic variables that classifies patients into homogeneous subsets by survival. Twenty-six pretreatment characteristics and six treatment-related variables were analyzed.

RESULTS

The years). Patients younger than 50 years old were categorized by histology (astrocytomas with anaplastic or atypical foci [AAF] versus glioblastoma multiforme [GBM]) and subsequently by normal or abnormal mental status for AAF patients and by performance status for those with GBM. For patients aged 50 years or older, performance status was the most important variable, with normal or abnormal mental status creating the only significant split in the poorer performance status group. Treatment-related variables produced a subgroup showing significant differences only for better performance status GBM patients over age 50 (by extent of surgery and RT dose). Median survival times were 4.7-58.6 months for the 12 subgroups resulting from this analysis, which ranged in size from 32 to 256 patients.

CONCLUSIONS

This approach permits examination of the interaction between prognostic variables not possible with other forms of multivariate analysis.

IMPLICATIONS

The recursive partitioning technique can be employed to refine the stratification and design of malignant glioma trials.

Improved survival duration in patients with unresected solitary brain metastasis using accelerated hyperfractionated radiation therapy at total doses of 54.4 gray and greater. Results of Radiation Therapy Oncology Group 85-28

BACKGROUND

Although there have been occasional reports of improved response with greater doses of irradiation for unresected brain metastases, dose escalation has not been systematically studied in a cohort of patients with solitary brain metastasis. The current study examines this group of patients to evaluate dose escalation using accelerated hyperfractionated radiation therapy (XRT) with regard to survival, patterns of failure, and toxicity.

METHOD

Radiation Therapy Oncology Group (RTOG) 85-28, a Phase I/II randomized trial of accelerated hyperfractionated XRT for patients with unresected supratentorial brain metastases, enrolled 153 patients with solitary brain metastasis. Whole brain dose was 32 Gray (Gy) administered in 1.6 Gy fractions twice a day with an interfraction interval of 4-8 hours. Boost dose was escalated to total doses of 48.0, 54.4, 64.0, and 70.4 Gy.

RESULTS

Acute and late toxicities were acceptable. The median survival time and 1-year survival rates were 4.9 months and 20% at 48 Gy; 5.4 months and 33% at 54.4 Gy; 7.2 months and 28% at 64 Gy; and 8.2 months and 37% at 70.4 Gy, respectively. Comparison of the upper three dose treatment arms to the 48 Gy treatment arm revealed a superior survival time with doses of 54.4 Gy and greater (P = 0.05). Improvement in neurologic function appeared to increase with dose escalation, with 25% of patients experiencing improvement at doses of 48 Gy, 38% at 54.4 Gy, 50% at 64 Gy, and 63% at 70.4 Gy (P = not significant).

CONCLUSION

A radiation dose response for survival time appears to exist with the use of accelerated hyperfractionated XRT for patients with unresected solitary brain metastasis.

Endometrial carcinoma. Influence of prognostic factors on radiation management

The earliest intracavitary radium treatment for uterine cancer was reported in 1908. Refinements reported during the next 20 years, using an intrauterine tube and colpostats or radium capsules, established a treatment philosophy of preoperatively irradiating uterine and parauterine tissues. Thus, preoperative intracavitary irradiation became entrenched as therapy for all endometrial cancers for the better part of four decades. In the 1950s and 1960s, the ability of external irradiation to eradicate cancer in regional lymphatic vessels prompted the use of pelvic field irradiation in Stage II and III and recurrent disease. The results of surgical exploratory studies in the 1970s established more refined criteria for preoperative or postoperative external pelvic irradiation in high-grade infiltrating Stage I cancers. In the 1980s, it became apparent that, for tumors with lymphovascular invasion, clear cell, and serous papillary histologic types, the disease spread to the upper abdomen and the paraaortic nodes might benefit from extended field and/or whole abdominal irradiation, with or without systemic bolus or concomitant continuous-infusion chemotherapy. In the 1980s, a subset of patients was identified with high-grade lymphovascular invasion clear cell and papillary serous histologic types or with positive peritoneal cytologic findings who were at high risk of failing in the paraaortic nodes and/or the upper abdomen for whom extended field or whole abdominal irradiation have been advocated. Given the fraction and dose limitation for a large abdominal field, the addition of systemic concomitant bolus or continuous infusion of chemotherapy currently is proposed to improve the control of intraabdominal failure in these high-risk patients.

New advances in radiation oncology for gynecologic cancer

In 1992, the American Cancer Society anticipates that there will be 1,130,000 new cases of invasive cancer diagnosed in the United States. About 66,500 will be invasive cancers of the cervix, uterus, and ovary. About 22,400 patients will die during 1992, with 50-60% of those deaths being due to persistent local regional disease. Data are available to suggest that a reduction in local failure will be reflected by an increase in survival free of disease. In 1992, major efforts are being made to reduce the incidence of local failure. Three areas in this regard are innovative uses of brachytherapy, intraarterial chemotherapy and radiation therapy, and continuous infusion chemotherapy and radiation therapy. These new techniques show significant reduction in local failure with associated improvement in survival. The data will be presented to illustrate the impact of these techniques.

Response of primary colon cancer cells in hybrid spheroids to 5-fluorouracil

We have measured the clonogenic survival of cells isolated directly from colon cancer surgical specimens and treated with 5-fluorouracil (5-FU). Enzymatically disassociated cells were incorporated into hybrid spheroids, consisting predominantly of nonproliferating HeLa feeder cells. Aliquots were exposed for 1.5 hr to a range of concentrations of 5-FU. From the decrease in clonogenic survival, as deduced from the frequency of colony formers among hybrid spheroids after chemical treatment, we were able to construct survival curves in 50% of the surgical specimens tested. A striking revelation was the presence of a resistant plateau in the survival curves, reminiscent of the solid tumor response to treatment with 5-FU. This resistance was absent in monolayer cultures. Evidence is presented that this resistance is due to the absence of, or delay in, cell cycle progression of cells residing in hybrid spheroids.

Genetic similarity of Candida albicans strains from vaginitis patients and their partners

The moderately repetitive sequence Ca3 was used to fingerprint strains of Candida albicans isolated from vulvovaginal infections of 10 women and strains isolated from their male partners. The Dendron software package was then used to compare the DNA fingerprints of these strains with those of vaginal commensals from women from the same geographical locale, vaginal commensals from women from a different geographical locale, and commensals from male partners of asymptomatic women from the same geographical locale. The results demonstrate that, in the majority of cases (8 of 10), strains from symptomatic patients and their partners are either identical or more similar to each other than to other strains, infecting strains do not represent a group genetically distinguishable from vaginal commensal isolates from women from the same geographical locale, and both infecting strains and commensals from individuals in the test locale can be distinguished from commensals obtained in another geographical locale. The results also suggest that women with vaginal infections are responsible for strain replacement in their male partners.

Potentiation of radiation lethality in mouse melanoma cells by mild hyperthermia and chloroquine

To test the hypothesis that radiosensitization by combined mild hyperthermia and chloroquine may be increased by the presence of melanin in treated cells, Cloudman melanotic mouse melanoma S91/6 cells, and the amelanotic S91/amel cells were incubated during a 3 h post-irradiation period with 0.03 mM chloroquine at 41 degrees C. A considerable increase in radiation lethality was observed (radiation potentiation factor > 1.6) in both cases. Addition of 0.1 mM isobutyl-methyl xanthine (IBMX), a promoter of melanin synthesis, to the growth medium of S91/6 cells 10 days before irradiation, did not further increase the lethality of radiation followed by combined heat and chloroquine treatment. Under these conditions, toxicity to unirradiated cells was slight. On the other hand, 10 microM chloroquine showed similar toxicity to unirradiated B-16 mouse melanoma cells, but did not increase radiation lethality. Factors other than melanin content therefore play a role in the potentiation of radiation lethality by mild hyperthermia and chloroquine.

Potentiation of radiation lethality in HeLa cells by combined mild hyperthermia and chloroquine

Evidence is presented for the interaction of X irradiation, slightly toxic levels of chloroquine, and mild hyperthermia in the inactivation of colony-forming ability in asynchronous HeLa cells. A three-way interaction was observed which resulted in the potentiation of radiation-induced lethality. There was little evidence of toxicity in unirradiated cells incubated for 3 h with 0.1 mM chloroquine at either 37 or 41 degrees C. The radiopotentiation factor, which is similar to the dose modification factor, was determined from dose-response curves by relating the reciprocal of the slope (D0) of the reference survival curve to that of the survival curve of cells receiving the combined postirradiation treatment with chloroquine and mild hyperthermia. Radiopotentiation factors larger than 1.7 were obtained irrespective of whether the reference D0's were obtained from survival curves for cells irradiated at 37 degrees C without drug or from cells receiving postirradiation treatment with heat or drug only.

Does extent of surgery influence outcome for astrocytoma with atypical or anaplastic foci (AAF)? A report from three Radiation Therapy Oncology Group (RTOG) trials

103 patients with the diagnosis of AAF were identified from the RT/BCNU arms of 3 RTOG malignant glioma trials. Pre-treatment tumor size was less than 5 cm for 48% and greater than or equal to 5 cm for 52%, and tumor sites were frontal lobe in 55%, temporal in 25%, and parietal in 16%. Surgery consisted of biopsy for 30%, partial resection for 56%, and total resection for 14%. Extent of surgery correlated with age, with 81% of patients less than 40 undergoing partial/total resection vs. 60% of those over 40 (P = 0.019). The median survival time (MST) of patients undergoing partial/total resection was 49 mo., vs. 18 mo. for those biopsied only (P = 0.002). Patients with frontal location had longer MST than those with non-frontal lesions (MST: 49 vs. 25 mo., P = 0.047), while no survival difference was apparent by univariate analysis of tumor size. Multivariate analysis demonstrated that only younger age, frontal location, and smaller tumor size correlated significantly with extended survival. Extent of surgery was not predictive. The close correlation between young age and extensive surgery obscures the survival advantage for greater surgery seen with univariate analysis. Smaller tumor size and frontal location favorably influence outcome even when adjusted by age.

High grade adenocarcinoma of prostate in smokers of ethnic minority groups and Caribbean Island immigrants

The degree of differentiation of 670 blacks and white patients treated from 1980-1990 for curative and palliative external beam radiation therapy and surgery at State University of New York Health Science Center at Brooklyn and Kings County Hospital were analyzed retrospectively, stratified according to race, age, smoking, and grade. In addition stage, birth place and median survival were also analyzed. Overall mean age was 69 years (Std. Dev. 8.97). 69% were blacks and 27.8% were whites. 65.4% were smokers and 34.6% were non-smokers. Smokers had high incidence of more invasive and high grade adenocarcinoma of prostate (p < or = 0.00005) compared to control group (non-smokers with prostate carcinoma). Statistically significant difference was found in the degree of differentiation of carcinoma of prostate in smokers compared to non-smokers. Smokers had 15.04% well, 27.07% moderate, and 57.89% poorly differentiated adenocarcinoma compared to non-smokers in which 37.1% were well, 45.16% moderate, and 17.74% poorly differentiated cancer of prostate (p < or = 0.00005). Sixty-three percent blacks and 40.16% whites had Stage D cancer (p < or = 0.00005). 68.3% smokers and 53.3% non-smokers had Stage D cancer (p = 0.01). Overall median survival for blacks was 74.04 months compared to whites of 115.73 months (p < or = 0.00005).

The prognostic significance of race and survival from prostate cancer based on patients irradiated on Radiation Therapy Oncology Group protocols (1976-1985)

A number of studies have identified race as a prognostic factor for survival from prostate cancer. To evaluate the prognostic significance of race in a controlled setting, we evaluated 1294 patients treated on three prospective randomized trials conducted by the Radiation Therapy Oncology Group between 1976 to 1985. One-hundred and twenty (9%) of the patients were coded as black, while 1077 (83%) of the patients were coded as white. Protocol 7506 included 607 patients with clinical Stage T3-T4Nx or T1b-T2N1-2. Protocol 7706 included 484 patients with clinical Stage T1b or T2 who were node negative. Protocol 8307 included 203 Stage T2b-T4 patients with no lymph node involvement beyond the pelvis. Univariate and multivariate analyses were used to assess the possible independent significance of race and other prognostic factors, including Gleason score, serum acid phosphatase, nodal status, and hormonal status. Protocols 7706 and 8307 revealed that race was not of prognostic significance for disease-free or overall survival by either univariate or multivariate analysis. Univariate analysis of Protocol 7506 revealed that the median survival for blacks was somewhat shorter (5.4 years vs. 7.1 years, p = 0.02). This difference persisted after a multivariate analysis. A higher percentage of blacks treated on 7506 had an abnormally elevated serum acid phosphatase compared to whites (p = 0.006), and the time to distant failure tended to be shorter (p = 0.07). These findings suggest that blacks treated on 7506 may have had more extensive disease at presentation. Based on these prospective randomized trials, it is most likely that the lower survival noted for black Americans with prostate cancer reflects the tendency for blacks to present with more advanced disease. Differences in access to care, the quality of care received, and the impact of co-morbid conditions may explain the lower survival reported for black Americans elsewhere in the literature.

A report of RTOG 8206: a phase III study of whether the addition of single dose hemibody irradiation to standard fractionated local field irradiation is more effective than local field irradiation alone in the treatment of symptomatic osseous metastases

Hemibody irradiation (HBI) in a single exposure is an effective and safe technique for palliation of symptoms due to widespread bony metastases (RTOG 78-10). The present study (82-06) sought to explore the possibility that HBI added to local-field irradiation might delay the onset of metastases in the hemibody effected, as assessed by bone scans and X rays, and decrease the frequency of further treatment. The results of this clinical trial establish that 800 cGy of HBI is indeed causes micro-metastases to regress, perhaps completely. A total of 499 patients were randomized to receive either HBI or no further treatment following completion of standard palliative local field irradiation (300 cGy x 10) to the symptomatic site. Improvement was seen in time-to-disease progression at one year, 35% for local + HBI versus 46% on the local-only control arm. Time-to-new disease in the targeted hemibody was also improved. At one year, 50% of patients on the local + HBI arm showed new disease compared to 68% on the local-only arm. Furthermore, the median time-to-new disease within the targeted HBI area was 12.6 months for the local + HBI arm versus 6.3 months for patients in the local-only arm. Time-to-new treatment within the hemibody segment was also delayed. At one year, 76% of the local only group had been retreated versus 60% in the local + HBI arm. There were no fatalities and no radiation pneumonitis was seen in the local + HBI arm. Overall, the incidence of toxicities was low (5-15%). The occurrence of severe hematopoetic toxicities were significantly different in the local + HBI arm, but they were transitory. One life-threatening thrombocytopenia occurred, for a limited time, indicating excellent tolerance to HBI. This clinical trial demonstrates that HBI has the potential to be used to treat systemic and occult metastases, particularly if both halves of the body can be treated.

Estimates of radiation absorbed dose for intraperitoneally administered iodine-131 radiolabeled B72.3 monoclonal antibody in patients with peritoneal carcinomatoses

Using a newly available model for determining estimates of radiation absorbed dose of radioisotopes administered intraperitoneally, we have calculated absorbed dose to tumor and normal tissues based on a surgically controlled study of radiolabeled antibody distribution. Ten patients with peritoneal carcinomatosis received intraperitoneal injections of the murine monoclonal antibody B72.3 radiolabeled with 131I. Biodistribution studies were performed using nuclear medicine methods until laparotomy at 4-14 days after injection. Surgical biopsies of normal tissues and tumor were obtained. The marrow was predicted to be the critical organ, with maximum tolerated dose [200 rad (2 Gy) to marrow] expected at about 200 mCi (7.4 GBq). In patients with large intraperitoneal tumor deposits, the tumor itself is an important source tissue for radiation exposure to normal tissues. Local "hot-spots" for tumor-absorbed dose were observed, with maximum tumor-absorbed dose calculated at 11,000 rad (11 Gy) per 100 mCi (3.7 GBq) administered intraperitoneal; however, tumor rad dose varied considerably. This may pose serious problems for curative therapy, especially in patients with large tumor burdens.