Clinical aspects of postirradiation sarcomas

The number of cancer patients who live longer and are cured of their disease is increasing. Many of them have received radiotherapy as part of their treatment. Postirradiation sarcoma (PIS), while still uncommon, is a complication which is appearing more frequently as the number of long-term survivors increases. Studies of the clinical characteristics of PIS, such as stage of disease, grade, survival, and prognosis, are therefore of increasing importance, and may lead to different strategies for early detection and prevention. In a literature review of PIS, we identified 344 cases with sufficient data for analysis of these clinical characteristics. In these selected cases, we found that: (a) PIS was most often diagnosed at an advanced stage and high grade; (b) most of the tumors were located in areas where radical surgery could not be performed; (c) the response rate to chemotherapy was almost always poor; and (d) most patients with PIS died from locally advanced and/or metastatic disease within a few months after diagnosis. PIS is a serious, usually fatal, late complication of radiotherapy and it should be weighed in the decision to use this modality of therapy. In the follow-up of cancer patients, a low threshold of suspicion for PIS is recommended in order to detect it early for possible resection. Because of the poor prognosis, more aggressive and investigative chemotherapeutic regimens are warranted.

Cholecystectomy and adenomatous polyps of the colon in women

The relationship between prior cholecystectomy and colon cancer in women has been a subject of recent research interest. No study has yet reported on cholecystectomy and adenomatous polyps, a precursor lesion for most colon cancers. This pilot case-control study interviewed 245 women who had undergone colonoscopy between 1983 and 1985 at Columbia-Presbyterian Medical Center with a structured telephone-administered questionnaire. Fifty-six were colon cancer cases, 105 were adenomatous polyp (AP) cases, and 84 were controls (without colonic neoplasia). Adjusted for age and educational attainment, the odds ratio for prior cholecystectomy among colon cancer cases compared to controls was 1.79 (95% confidence limits, 0.59 to 5.44) and 2.26 for right-sided colon cancer cases (95% confidence limits, 0.61 to 8.42). Despite a lack of statistical power, these estimates are consistent with earlier reports. The odds ratio for adenomatous polyp cases was 1.02 (95% confidence limits, 0.40 to 2.64), suggesting no association between prior cholecystectomy and adenomatous polyps. These preliminary findings are currently being explored in a large-scale case-control study.

Colonic neoplasms in asymptomatic first-degree relatives of colon cancer patients

First-degree relatives of colon cancer patients are at elevated risk for developing colorectal neoplasms. In order to assess the potential usefulness of screening by colonoscopy in this high-risk population, we reviewed the records of 48 colonoscopies performed on asymptomatic patients who were self- or physician-referred for colonoscopy because of a history of one or more first-degree relatives with colon cancer. Twelve (25%) had at least one adenomatous polyp, but no significant atypia was detected. No cancers were detected. One third of the lesions were beyond the reach of a flexible sigmoidoscope. This apparent increase in the prevalence of adenomas was most striking (46%) among men over the age of 50. These preliminary results demonstrate that colonoscopy is effective in detecting and removing adenomatous polyps in a substantial fraction of asymptomatic patients whose sole risk-factor is being a first-degree relative of a patient with colon cancer. Further studies in larger populations are warranted to determine the use of colonoscopy in screening these high-risk individuals.

Cholecystectomy and adenomatous polyps of the colon in women

The relationship between prior cholecystectomy and colon cancer in women has been a subject of recent research interest. No study has yet reported on cholecystectomy and adenomatous polyps, a precursor lesion for most colon cancers. This pilot case-control study interviewed 245 women who had undergone colonoscopy between 1983 and 1985 at Columbia-Presbyterian Medical Center with a structured telephone-administered questionnaire. Fifty-six were colon cancer cases, 105 were adenomatous polyp (AP) cases, and 84 were controls (without colonic neoplasia). Adjusted for age and educational attainment, the odds ratio for prior cholecystectomy among colon cancer cases compared to controls was 1.79 (95% confidence limits, 0.59 to 5.44) and 2.26 for right-sided colon cancer cases (95% confidence limits, 0.61 to 8.42). Despite a lack of statistical power, these estimates are consistent with earlier reports. The odds ratio for adenomatous polyp cases was 1.02 (95% confidence limits, 0.40 to 2.64), suggesting no association between prior cholecystectomy and adenomatous polyps. These preliminary findings are currently being explored in a large-scale case-control study.

The impact of colonoscopy on the early detection of colonic neoplasms in patients with rectal bleeding

A retrospective analysis was made of 372 consecutive patients who underwent colonoscopy because of rectal bleeding. The three distinct patterns of bleeding studied were chronic (224 cases), recent major (93 cases), and acute bleeders (55 cases). In 50% of the cases, colonoscopy detected a lesion other than diverticula. These lesions consisted of several forms of colitis, arteriovenous malformations (AVMs), ulcers, and most importantly, neoplasms in 34% of the cases. In 13% of the cases, an invasive neoplasm was detected and 76% of them were early stage (Dukes A or B). A third of the neoplasms were located proximal to the splenic flexure. Among patients with a negative barium enema, 35% had a neoplasm detected on colonoscopy. These findings were similar for the three distinct patterns of rectal bleeding studied. These data support the need for colonoscopy in all types of rectal bleeders, regardless of the results obtained by BE.

Multiple primary neoplasms in association with prostate cancer in black and white patients

The current study follows up the 983 patients who were diagnosed as having prostate cancer at the Columbia-Presbyterian Medical Center in New York City between 1970 and 1979 and of whom 106 (11.5%) developed a multiple primary malignant neoplasm (MPMN) in addition to their prostate cancer by January 1, 1986. Of the 283 black patients, 32 (11.3%) developed an MPMN involving 35 sites excluding prostate. Of the 636 white patients, 74 (11.6%) developed an MPMN in association with their prostate cancer. Comparing observed incidence rates to expected on the basis of SEER incidence data, two malignant tumors, urinary bladder cancer and malignant lymphoma, appeared to occur in excess in the present series of patients. The excess of urinary bladder cancer in our series could be explained by detection bias due to the routine use of cystoscopy. The excess incidence of lymphoma in our series appears significant but its etiology is unexplained.

Serum cholesterol levels in adenomatous polyps and cancer of the colon. A case-control study

A series of recent studies has shown an association between low serum cholesterol level and cancer, particularly of the large bowel. To explore this issue, serum cholesterol measurements were collected from 244 patients with adenomatous polyps of the colon, 182 patients with Dukes' A or B colon cancer, and 688 hospital controls who were diagnosed between 1979 and 1981 at a New York City hospital. The mean serum cholesterol levels were lower for patients with cancer (207.2 mg/dL) than for controls (219.5 mg/dL), with patients with Dukes' B cancer accounting for most of the difference. Patients with adenomatous polyps (219.8 mg/dL) were similar to controls. After adjustments for nutritional status using the serum albumin level, there were no statistically significant differences among any of the groups. We conclude that the low serum cholesterol level previously associated with malignancies, and colon cancer in particular, is a consequence rather than a cause of the cancer.

Recurrence rates for colorectal polyps

Of 276 patients who underwent an initial colonoscopic polypectomy for adenomatous polyps over a 45-month period, 118 subsequently had one or more repeat screening colonoscopies. The mean follow-up time was 26 months with an overall polyp recurrence rate of 30%. Analysis of these data retrospectively suggests that the bulk of the recurrences occurred within the first year. Increasing age was found to be a significant risk factor for polyp recurrence. Asymptomatic recurrence of adenomatous polyps detectable by colonoscopy is a common occurrence in postpolypectomy patients. Prospective studies utilizing colonoscopy as a screening tool are needed to establish a rational screening policy for this high-risk group.

How accurate are patient histories?

Recently there has been a large increase in the use of emergency rooms and screening clinics for the delivery of primary medical care. In these impersonal health care settings physicians must often rely on medical histories obtained from patients over the course of a few minutes without benefit of old records or previous acquaintance with the patient. Few data are available on the accuracy of these histories. In this preliminary investigation we used the history of past admission to the hospital as a marker for the validity of patient responses in an emergency room. Overall, 71 of 114 patients with known previous admissions gave accurate responses when asked why they had previously been admitted to the hospital (62 +/- 4.5 percent). Disease category appears to be a relevant factor in predicting the accuracy of the response, but the number of patients was too small to evaluate other subgroups of patients. Future studies should involve sufficient patients to evaluate the individual contributions of patient characteristics in predicting the accuracy of medical interviews.

The use of agarose in the determination of anchorage-independent growth

At the present time, growth in agar suspension is one of the best in vitro correlates of tumorigenicity. Growth in agarose, however, has not been evaluated extensively as an in vitro criterion for tumorigenicity. In the present study we have tested 19 cell lines, including six mouse-human hybrids, for growth in agarose and agar in the presence and absence of exogenous hypoxanthine. None of the six nontumorigenic cell lines grew in agar or agarose. Ten of the 13 tumorigenic cell lines grew in both agar and agarose with about equal efficiency. The remaining three tumorigenic cell lines grew well in agarose but poorly or not at all in agar. Hypoxanthine did not stimulate the growth in agar or agarose of any of the cell lines except BHK. We conclude that growth in agarose may be a more sensitive marker for tumorigenicity than growth in agar and that BHK is exceptional in its sensitivity to supplemental purines.

Growth limitation of BHK-21 cells and its relation to folate metabolism

The role of folate metabolism in growth control in monolayer and suspension cell cultures was studied in three related cell lines: BHK-21, polyoma-transformed BHK-21 (PyBHK), and an aminopterin-resistant derivative of BHK-21 (A5). BHK-21 cells had extremely low levels of dihydrofolate reductase, PyBHK had higher levels, and A5 had extremely high levels. Hypoxanthine and thymidine together, but not individually, induced BHK-21 to grow in agar, and stimulated its growth in agarose and monolayer culture. PyBHK and A5 grew spontaneously in agar, and hypoxanthine plus thymidine had little or no effect on their growth either in suspension or in monolayer cultures. We found that exogenous folinic acid, a derivative of folate metabolism that bypasses the function of dihydrofolate reductase, mimicked the growth-stimulatory effects of exogenous hypoxanthine plus thymidine BHK-21. We conclude that the growth limitation of BHK-21 in suspension culture is due, in part, to a deficiency of dihydrofolate reductase. This enzyme deficiency limits nucleoside synthesis and can be overcome by supplying end products of this pathway.

Creutzfeldt-Jakob disease: familial clustering among Libyan-born Israelis

Creutzfeldt-Jakob disease was studied among Libyan-born Israelis, in whom the disease appears with unusual frequency. Interviews with relatives of deceased victims revealed statistically significant clustering within families. The results suggest either a common source of exposure or a genetic influence on susceptibility to the virus.