Exemestane 25 mg once daily seems to be an attractive alternative to chemotherapy for the treatment of patients with metastatic breast cancer after multiple hormonal therapies have failed.

SUMMARY The prevalence of methane production in an adult population of 256 subjects was 41%, but it was significantly higher in females (49 %), than males (33 %). When the population was subdivided into ethnic groups, Caucasians (48 %) and Blacks (45 %) had significantly more methane producers than Orientals (24%) and Indians (32 %). When the ethnic groups were analysed by sex, female Caucasians had the highest prevalence (58 %), significantly more than Caucasian males, Oriental males, and females and Indian males. In contrast with previous studies, a single dose of lactulose was found to significantly increase breath methane concentrations in six out of 12 methane producers, but not in 25 non-methane producers from the population study. In conclusion, any studies on breath methane must take into consideration the ethnic origin of the subjects and, contrary to previous advice, substrate intake, especially undigestible carbohydrates. Furthermore, a single breath sample may miss up to one-fifth of methane producers.A proportion of intestinal methane produced by anaerobic methanobacteria in the colon is excreted into the breath.' In one series methane was found in the breath in only one-third of a population of 280 adults.' There appeared to be a familial tendency and environmental factors were also thought to play a part. The ingestion of non-absorbable carbohydrates, such as lactulose and raffinose,' 2 appeared not to influence methane production. In this paper we report a study on the prevalence of methane production in a population consisting of four different ethnic groups, together with the acute effect of a single dose of the non-absorbable disaccharide, lactulose, on methane production. Methods SUBJECTSThe pulmonary excretion of methane was studied in a population of 256 healthy volunteers from the staff of two hospitals. The subjects were enrolled by two of us (PP, MFB) touring wards and laboratories asking for volunteers. One hundred and eighteen *Address for reprint requests: Dr L M Blendis, 9th Floor, Eaton Wing, Toronto General Hospital, 585 University Avenue, Toronto, Ontario, M5G 1L7, Canada.Received for publication 29 July 1980 were male and 138 female, with ages ranging from 19 to 59 years with an average of 34 years. None of these subjects was taking antibiotics or laxatives for at least seven days before the sampling. The group was investigated as a whole and then divided into subgroups according to their ethnic origin. This was established by the ethnic characteristics of their appearance and their place of birth. Only three of the 256 subjects (Indians) were related. Duplicate endexpiratory breath samples were collected via a modified Haldane-Priestly tube into 20 ml plastic syringes attached to the side arm of the tube by a three-way stopcock.3 The methane content of both syringes was measured by gas chromatography, using a Carle AGC-311 equipped with a hydrogen flame detector. Breath components were separated at room temperature on a 2 m X 6-10-3 m (length X inner diameter) column, packed ...

One hundred and twelve post menopausal or post oophorectomy women with advanced breast cancer (BC) who had all previously had aminoglutethimide (AG) were treated with the potent aromatase inhibitor 4-hydroxy androstenedione (4-OHA). Twenty three women (21%) had a partial response to 4-OHA while another twenty five patients (22%) had stabilization of previously progressing disease. Patients responded to 4-OHA both after previously responding to then relapsing on, and after failing to respond to aminoglutethimide. Toxicity was minimal. This study shows that potent aromatase inhibition with 4-OHA is effective in women with advanced BC who have already been treated with a less potent aromatase inhibitor, and suggests that relative changes in oestrogen levels may be more important than absolute levels.

Abstract. Biochemical markers of bone turnover were measured in fasting urine and blood samples obtained from 38 postmenopausal women with previous surgical treatment of breast cancer combined with adjuvant chemotherapy, tamoxifen, or placebo. Significantly elevated urinary pyridinoline as nmol mmol-' creatinine (47.5 and 42.5 in tamoxifen and placebo treated patients compared with 26.3 in normal controls, both P < 0.001) and deoxypyridinoline (1 1.9 and 10.5 compared with 6.3, P < 0.001 and P = 0.002 respectively) were found with unchanged urinary hydroxyproline, serum alkaline phosphatase and procollagen I carboxyterminal peptide (PICP). These findings suggest enhanced bone resorption resulting from the humoral osteoclast activating effect of the previous breast cancer or underlying carcinoma recurrence. Alternatively the raised pyridinium excretion might indicate an altered crosslinking composition of bone collagen. No specific effect on bone metabolism was found with tamoxifen treatment as all measured parameters were similar in both tamoxifen ex-users and non-users. This confirmed the safety of tamoxifen therapy with respect to bone.