Cholecystectomy as a risk factor for colorectal cancer: a meta-analysis.

BACKGROUND: It has been suggested that there is an increased risk of colorectal cancer after cholecystectomy due to increased levels of secondary bile acids. Some studies suggest the risk is higher for women and for the development of right-sided tumours. METHODS: A review of the literature yielded 95 relevant studies, of which 35 were suitable for a meta-analysis involving age- and sex-matched controls. RESULTS: The pooled odds ratio for a positive association between cholecystectomy and colorectal cancer was 1.11 (95% confidence interval (CI), 1.02 to 1.21). For women the odds ratio was 1.14 (95 % CI, 10.01 to 1.28) and for right-sided cancer 1.86 (95% CI, 1.31 to 2.65). CONCLUSIONS: It is possible that this small observed association may be due to a publication bias for positive results or bias within the included studies. If it is indeed a real effect, the risk to an individual is very small.

The relationship between cholecystectomy, unoperated gallstone disease, and colorectal cancer. A necropsy study.

BACKGROUND: There may be an increased risk of colorectal cancer after cholecystectomy, but the literature is not consistent. It is also possible that any risk might be associated with gallstones rather than cholecystectomy. METHODS: In a prospective necropsy study of 8563 cases, all 219 cases of a previous cholecystectomy were pair-matched to subjects with gallstones and to subjects with a normal gallbladder. In a second study all 192 cases of colorectal cancer were pair-matched to cancer-free subjects. RESULTS: The odds ratio (OR) for developing colorectal cancer after cholecystectomy compared with a normal gallbladder was 1.0 (95% confidence interval, 0.30-3.34) and with unoperated gallstones was 0.88 (0.27-2.76). CONCLUSIONS: This study fails to support an association between cholecystectomy or gallstones and colorectal cancer. For those cases of colorectal cancer versus controls, the OR for previous cholecystectomy was 0.70 (0.23-2.04) and for gallstone disease was 0.93 (0.58-1.48).

Color Doppler sonography in the evaluation of palpable breast masses.

OBJECTIVE: A prospective study was performed to determine the value of high-resolution color Doppler sonography in the evaluation of palpable solid breast masses. SUBJECTS AND METHODS: One hundred thirty-one consecutive breast lesions were characterized as benign, malignant, or indeterminate on the basis of their sonographic appearance. The number of blood vessels was estimated, the Doppler spectrum for each vessel was characterized, and the maximum velocity was recorded. Mammography was performed in most cases. Histology was obtained in all cases. RESULTS: Predictions based on sonography alone were correct in 74% of benign lesions and 63% of malignant lesions (p < .001). Blood flow was demonstrated in 87% of malignant lesions and in 68% of benign lesions (p = .0105). Malignant lesions were larger than benign lesions (p = .004) and showed a significantly greater number of vessels (p < .001) and significantly higher maximum velocity (mean, 34.2 vs 19.2 cm/sec; p < .001). Patients with malignant lesions were significantly older (p < .001). When age, size of lesion, and sonographic morphology were controlled, the presence of blood flow did not aid in diagnosis. However, in lesions with blood flow, when spectral patterns and maximum velocity were analyzed, a logistic model combining these parameters with age, size, and sonographic morphology gave an overall sensitivity of 94%, specificity of 93%, and positive predictive value of 92%. Mammography yielded useful additional information, particularly for indeterminate lesions. CONCLUSION: Maximum velocity and spectral patterns on Doppler analysis are useful indicators of breast malignancy, but only if the patient's age, the size of the lesion, and the sonographic morphology are also considered. The best use of color flow imaging is in combination with mammography.

Trial of aminoglutethimide vs hydrocortisone as second-line hormone treatment of advanced breast cancer.

In a randomized trial of second line hormone therapy 56 postmenopausal women with advanced breast cancer received low dose aminoglutethimide (AGT) 125 mg twice daily without hydrocortisone (27 patients), or hydrocortisone (HC) 20 mg twice daily (29 patients). The two groups were well-matched for previous response to tamoxifen (TAM) therapy (AGT (35%) vs HC (32%)) and for relapse on adjuvant TAM. The mean age of the two groups was 69.2 years (AGT) and 63.2 years (HC). Liver metastases were present in 29% (AGT) and 33% (HC). The response rates were 11% (AGT) and 21% (HC). At 12 months the failure of treatment rate was 80% (AGT) and 70% (HC). Survival at 12 months was 50% for both groups. At 12 months 5/12 survivors were still on AGT and 8/12 on HC. These preliminary findings have so far failed to show any statistical difference in tumour response, time to treatment failure or survival between low-dose AGT and HC as second-line hormone treatment post-tamoxifen in advanced breast cancer.

A survey of antimicrobial prophylaxis in elective colorectal surgery in New Zealand.

In 1988 a survey of New Zealand general surgeons was conducted, by post, on the subject of routine antimicrobial prophylaxis for elective colorectal surgery. Surgeons who gave routine prophylaxis were asked for details of their regimens; those who did not were asked for their reasons. One hundred and seventy-five questionnaires were distributed and 167 were returned. Of these, 124 came from surgeons with a colorectal practice, and 118 of the 124 surgeons satisfactorily completed the questionnaire. Routine antimicrobial prophylaxis was given by 96.6% (114 of 118). Of the 114 surgeons prescribing prophylaxis, one antimicrobial agent was used by 36.8%, two were employed by 53.5% and three or five were used by the remainder. The most commonly used (74.6%) antimicrobial agents were cephalosporins which were prescribed, alone or in combination with a nitroimidazole. The most frequent duration (46.4%) of antimicrobial administration was a combination of both the peri- and postoperative periods. When antimicrobial spectrum, route and duration of administration were all taken into account, 49.1% (56 of 114) were considered to give satisfactory regimens. Excessively protracted administration was the most frequent reason for unsatisfactory classification. The results of this survey demonstrate serious deficiencies in the practice of antimicrobial prophylaxis in elective colorectal surgery. These should be addressed through a programme of continuing education.