Biomedical subjects

M B Dockerty

Publications and source records attributed to M B Dockerty.

At least 19 recordsLinked to original sources

PubMed1987

Carcinoid tumor of the appendix: treatment and prognosis.

In a long-term study of 150 unselected patients with carcinoid tumors of the appendix, we found that the neoplasms were usually less than 1.0 cm in largest dimension and discovered as an incidental finding during surgery performed for other reasons. Metastases were observed with none of the 127 appendiceal carcinoids less than 2.0 cm in largest dimension, with 3 of the 14 lesions greater than or equal to 2.0 cm but less than 3.0 cm in greatest dimension, and with 4 of the 9 lesions greater than or equal to 3.0 cm. Paradoxically, the patients with the larger tumors and metastases were younger than those with smaller and clinically benign tumors. The median age of patients with tumors greater than or equal to 2.0 cm was 31 years and that of those with metastases was 29 years, as compared with a median age of 42 years in patients with nonmetastasizing tumors less than 2.0 cm. We conclude that simple appendectomy is adequate treatment for patients with apparently localized tumors less than 2.0 cm in largest dimension. We have not observed any recurrences or metastases among 122 such patients followed for a median time of more than 26 years. Simple appendectomy is probably also appropriate treatment for lesions greater than or equal to 2.0 cm in elderly patients or in those at high operative risk. Right hemicolectomy seems justified only in young patients with tumors greater than or equal to 2.0 cm who have a low risk of operative morbidity or mortality. Vascular involvement and invasion of the mesoappendix are features that may favor a more radical approach.

Adolescent↗

PubMed1983

Trends in right and left-sided colon cancer.

The increasing ratio of proximal to distal colorectal carcinomas was confirmed in this population-based study of 668 new cases diagnosed among Rochester, Minnesota residents between 1940 and 1979. The change was due to a rise in the incidence of proximal lesions (from 15.1 per 100,000 person-years in 1940-59 to 17.3 per 100,000 in 1960-79) and a simultaneous fall in the incidence of distal lesions (from 35.5 to 28.2 per 100,000 person-years). Changes in definitions or referral patterns played no role in these observations, although improved diagnostic capabilities may have had an impact on the incidence of proximal lesions. These discrepant changes in incidence strongly suggest that proximal and distal colonic cancers are different diseases or have a different pathogenesis. The changing incidence rates were not associated with consistent differences in clinical characteristics at the time of initial diagnosis.

Adenocarcinoma↗

PubMed1983

A decline in carcinoma of the stomach. A diagnostic artifact?

During the past 50 years or more, a dramatic decline in the mortality from gastric carcinoma has been observed in virtually every country in the world, including the United States. Some investigators suspect that this decline is due to refinements in the diagnosis and classification of abdominal malignancies rather than being a true decline in the incidence of gastric cancer. Because the record system in Rochester, Minnesota, ensures the identification of virtually every patient in the local population with a serious illness, and the level of diagnosis is high, it seemed appropriate to study the incidence and long-term trends of gastric cancer in this community. Trend analysis for the period 1935 through 1979 revealed a consistent decline in the incidence of gastric carcinoma whether death certificates as the sole source of cases were included or not. Analysis of either all clinically confirmed or only tissue-confirmed cases revealed a statistically significant decrease in stomach carcinoma throughout the study period. These declines were observed even if only the more recent periods (1955 through 1979) were examined. The reasons for this finding remain obscure, but the study suggests that improvements in diagnostic accuracy alone cannot account for this remarkable downward trend in gastric malignancy.

Adolescent↗

PubMed1981

Cholecystectomy and carcinoma of the colon.

After cholecystectomy the concentration of secondary bile acids in the bile increases. These bile acids have been incriminated in the pathogenesis of carcinoma of the colon. Hence the hypothesis that cholecystectomy predisposes to the development of carcinoma of the colon. To test this hypothesis, 1681 residents of Rochester, Minnesota (460 males and 1221 females), who underwent cholecystectomy during 1950-69, were followed up. Carcinoma of the colon developed in a higher-than-expected number of patients. However, the association was significant only in females (relative risk 1.7; 95% confidence interval 1.1-2.5) and even stronger for right-sided carcinoma of the colon (relative risk 2.1; 95% confidence interval 1.1-3.6). These data support the hypothesis that cholecystectomy may be a predisposing factor in the development of cancer of the colon in women.

Aged↗

PubMed1979

Lack of evidence for cancer due to use of metronidazole.

Experimental studies have shown that metronidazole is carcinogenic in rodents and mutagenic in bacteria. In 771 women given metronidazole for the treatment of vaginal trichomoniasis, more cancers developed than had been expected after exclusion of carcinoma of one uterine cervix (observed, 24 cases; expected on the basis of the Connecticut Tumor Registry, 21.7; expected on the basis of the Third National Cancer Survey, 18.4). However, the excess was not statistically significant (P greater than 0.05). The observed and expected numbers of breast-cancer cases were the same, but four lung-cancer cases were observed, whereas 0.6 would have been expected. This finding is confounded by the fact that all four lung cancers developed in women who were smokers. Overall, we observed no appreciable increase in cases of cancer.

Adolescent↗

PubMed1979

Ovarian cancer: incidence and case-control study.

The incidence of ovarian cancer in Rochester, Minnesota over the 40-year period 1935 through 1974 was determined; and risk factors for epithelial ovarian cancer occurring in Rochester from 1945 to 1974 were examined in 116 patients and 464 controls. Among the characteristics studied, only nulliparity was found to be a significant risk factor--relative risk 1.8. Other suspected risk factors--including hypertension, obesity, age at menopause, prior therapeutic pelvic radiation, and prior exposure to exogenous estrogen--were found not to differ significantly between patients and controls. The ovarian cancer patients were found to have a significantly lower frequency of prior hysterectomy and of unilateral oophorectomy than the control group. Thus out data show that hysterectomy, even when one or both ovaries are preserved, is associated with a lower risk of subsequent ovarian cancer.

Adolescent↗

PubMed1977

Exogenous estrogen and endometrial carcinoma: case-control and incidence study.

Recent independent case-control studies have indicated that treatment with exogenous estrogen is associated with an increase in the risk of endometrial cancer. This question was studied in Olmsted County, Minnesota, by identifying all cases of endometrial cancer among residents over a 30 year period (1945 through 1974) and by matching four controls to each of the 145 patients. The rate of past exposure to any exogenous estrogen for any duration was about the same for patients as for controls. However, the estimated relative risk of endometrial cancer associated with conjugated estrogen treatment of 6 months or longer was 4.9 (P less than 0.01), and this increased to 7.9 (P less than 0.01) with exposure for 3 years or longer. The risk increased with larger doses (1.25 mg. or more) and continuous administration of conjugated estrogens. The incidence of endometrial carcinoma over the three decades of the study, corrected for an increasing rate of hysterectomy, was constant. Thus to this time, the low rate of use of conjugated estrogens in this region over the past 30 years apparently has not had an appreciable impact on the incidence of endometrial cancer.

Dilatation and Curettage↗

PubMed1976

Clear-cell adenocarcinoma of the vagina and cervix: survival data.

Survival data on 36 patients with clear-cell adenocarcinomas are reported: seven with vaginal lesions and 29 with cervical lesions. Although the tumor responds to present treatment modalities, it tends to be associated with early lymph node involvement, thus making early diagnosis essential. Radiation as a primary therapeutic measure has often been followed by late recurrence, though many patients with these tumors were treated by older, low-energy modalities.

Adenocarcinoma↗

PubMed1976

Primary transitional cell carcinoma of the prostate.

The symptoms and physical findings in patients with transitional cell carcinoma of the prostate were similar to those in patients with prostatic adenocarcinoma. Usually the neoplasm was poorly differentiated and advanced when the diagnosis was first established. Osseous metastases were commonly osteolytic. Frequently, elevations of serum alkaline or acid phosphatase levels were associated with metastasis. Tartrate-inhibited fractions of the serum acid phosphatase were not elevated. The best form of treatment is radical ablation of the prostate and radiation therapy is next best. Because these neoplasms are not hormonally dependent, hormonal manipulation is not indicated. Prognosis for patients with this malignancy is guarded.

Acid Phosphatase↗

PubMed1976

Status of the contralateral ovary in encapsulated low grade malignant tumors of the ovary.

The incidence of bilateral involvement in carcinoma of the ovary is shown to be relatively high. This is true for the different histologic type of malignant lesions and even when the ovary is grossly normal in appearance and on palpation. Only when carcinoma of the ovary is low grade, intracystic, unruptured and nonadherent and is in a young woman desirous of childbirth can it be managed conservatively.

Adenocarcinoma↗

PubMed1974