Charles R. Smart

Efficacy of breast cancer screening by age. New results swedish two‐county trial

Background. Several studies have found a smaller effect of breast cancer screening on breast cancer mortality in women aged younger than 50 years compared with older women. Various possible reasons have been suggested for this, but none firmly is established.

The fall in incidence of prostate carcinoma : On the down side of a prostate specific antigen induced peak in incidence : Data from the Utah cancer registry

In the 1980s, prostate specific antigen (PSA) came into wide use as a prostate carcinoma screening and detection method in the United States. Following the introduction of PSA, the age‐adjusted incidence of prostate carcinoma reported by the Surveillance, Epidemiology, and End Results (SEER) program in the United States rose rapidly (from 84.4/100,000 in 1984 to 163/100,000 in 1991). When an increase in incidence is observed following the introduction of a screening method, a subsequent decrease in incidence may be expected as prevalent cases are removed from the population (a cull effect). Incidence rates may also fall due to factors such as decreased intensity of screening. The Utah Cancer Registry data were examined for a decrease in prostate cancer incidence.

Low cancer incidence and mortality in Utah

Utah cancer mortality for the years 1950–1969 and morbidity for the years 1966–1970 are reported. Utah had 18% fewer cases of cancer than expected based on the Third National Cancer Survey, and 24% fewer cancer deaths than expected based on national mortality data. Cancer sites associated with cigarette smoking and alcohol use accounted for nearly half of these differences. Several major sites not strongly associated with smoking showed lower incidence and mortality than expected. These included pancreas, colon, rectum, female breast, uterine cervix and ovary. A marked excess occurrence above expectation was observed for cancer of the lip. Some possible explanations of these findings are discussed, including some of the unique aspects of the Utah population.

Estimated median survival times of patients with colorectal cancer based on experience with 9,745 patients

From the End Results Group file at the National Cancer Institute, 9,745 colorectal cancer patients diagnosed from 1965 through 1971 and classified as adenocarcinoma NOS were selected to evaluate the joint effect of various prognostic factors on MST. A technic was developed which enables a physician to estimate the MST for a patient with a given set of patient/disease characteristics. The results are also summarized in an appendix, allowing the physician to bypass the calculation and refer directly to the MST. These results will aid the physician in determining whether a patient is at sufficiently high risk to warrant adjuvant therapy. The survival experience of this broad historical group of patients with varying prognostic factors can also serve as a basis for comparison of results of studies on highly selected patients treated in various experimental ways.

Stage-shift cancer screening model

A stage-shift cancer screening model is developed in the context of a randomized controlled trial (RCT) of cancer screening. In the model, detection by screening causes the time of diagnosis of the cancer to be advanced so that either the stage at diagnosis is shifted from one stage to the next lower one or the stage of diagnosis is unchanged but the cancer is diagnosed earlier in the stage. These are called external and internal stage shifts, respectively. At each stage the extent of the external and internal shifts and any associated mortality benefits are estimated. Further, the model allows the interrelationships of these benefits within and between stages to be delineated. This then allows us to better understand the results of the RCT. Data from a completed breast cancer screening RCT are used to illustrate the application of the model and its value in improving our understanding of the trials results.

EARLY RESULTS OF COMBINED RADIATION AND CHEMOTHERAPY IN TREATMENT OF MALIGNANT TUMORS.

The knowledge of the effectiveness of adequately administered radiation therapy in achieving palliation and regression of certain types of malignant tumors and recent reports suggesting at least some effectiveness with the systemic use of chemotherapeutic agents in similar cases (1, 10) have precipitated an interest in the possibility of increasing therapeutic effectiveness by the use of these two modalities in combination. Published reports of such combined therapy have suggested an increased tumor response as compared to either method alone (4, 5, 8). In this series of cases treated with combined radiation and chemotherapy the results will be on the basis of patient survival; or in those instances where the patient is still alive, on objective evidence of tumor response. Because of the inherent dangers of the two therapy modalities, we are aware that premature conclusions can prove harmful in the long run. Case Selection This report is based on 99 cases of solid tumors. No patients with a diagnosis of l...

Diagnosis of minimal breast cancers in the bcddp. The 66 questionable cases

Of 1,810 breast cancers detected in the NCI/ACS Breast Cancer Detection Demonstration Projects, 592 were less than 1 cm in diameter and considered minimal; and tissue slides from 506 of them were available for retrospective review by a panel of pathologists. The initial report of this review indicated that in 66 cases the pathologic features of the presented slides were not sufficient for diagnosis of cancer. Subsequent investigation revealed that, through computer error, the slides submitted in 2 of these 66 cases were not from the lesions in question but from blind biopsy of the contralateral breast. Further review by the pathology panel of tissue from 38 of the 64 remaining cases determined that 16 of the remaining lesions were indeed cancers or borderline malignant lesions. This then left 48 cases in doubt. Only biopsy had been performed in 11 of them, and some form of mastectomy in the other 37. The original pathologic opinion had been divided in 30 of these, and the mastectomy had been delayed for 1 day to 7 months after the biopsy. In only 7 of the 48 questionable cases was definitive treatment carried out at the time of biopsy. All in all, these findings reflect sound, responsible surgical judgment. Cancer 43:848–850, 1979.

Side-Effects of Combined Radiation and Chemotherapy in the Treatment of Malignant Tumors

In a review of 99 cases of advanced solid tumors treated by a combination of irradiation and chemotherapy, it became apparent that toxic reactions capable of altering proposed treatment plans, even to requiring hospitalization, were frequent. Such reactions assume great importance in evaluating the response of any treatment technic. A high incidence of severe side-reactions, dangerous and debilitating to the patient, could well discourage therapy programs which produce only slightly better statistical improvement in the treatment of disease. In using therapeutic modalities in combination, the side-effects of each may become intensified. Great care must be taken not just in the treatment of these side-effects, but also in their anticipation. The patient must be questioned daily concerning minor symptoms in an effort to intercept and prevent the onset of major toxic reactions. In our series we have used predominantly 5-FU in combination with radiation. In a few cases, Actinomycin D, Mitomycin C, and chloram...