内海 俊明

Purpose: The incident at the Fukushima Daiichi nuclear power station in 2011 has again raised concerns with the public regarding radiation exposure, especially so in medical workers and patients undergoing treatment involving the use of radiation. Radioisotopes are currently used during sentinel node navigation surgery (SNNS) in operating rooms without radiation monitoring. To re-evaluate the safety issues, the potential effective dose (E poten) from 99mTc-tin (-Sn) colloid in breast cancer surgery was estimated and personal dose equivalents, H p(10) and H p(0.07), were measured during SNNS. Materials and methods: Seventeen breast cancer patients were enrolled. One day before SNNS, 99mTc-Sn colloid was injected around the tumor and radiation exposure rates were measured using survey meters. Personal dose equivalents for the surgical workers were measured. H p(10) and H p(0.07) for the body and H p(0.07) for the hands were recorded using semiconductor detectors and ring-type glass dosimeters. Results: The maximum E poten was 29 μSv per 74 MBq injection. The maximum H p(10) for the primary and assisting surgeons, nurse, and anesthetist was 3.7, 1.4, 0.3 and 0.6 μSv per SNNS, respectively. The maximum H p(0.07) for the hands was 100 μSv. Maximum radiocontamination 20 times higher than background (0.05 μSv/h) was detected in bloody gauze. Conclusion: The workers' radiation dose exposure from SNNS was not high, although radiation management such as a temporary cooling off period may be required. © Ejiri et al.

Estrogens play an important role in the pathobiology of breast cancer. In postmenopausal women, peripheral synthesis of estrogens from adrenal/ovarian androgens, dehydroepiandrosterone (DHEA) or androstenedione (Adione), by estrogen-metabolizing enzymes is important. Besides estrone (E1) and estradiol (E2), androgen metabolites, such as androstene-3 beta, 17 beta-diol (Aenediol) or 5 alpha-androstane-3 beta, 17 beta-diol (Aanediol), are known to have estrogenic functions, although they have been studied much less in breast cancer. To precisely elucidate steroid metabolism in breast cancer patients and to identify the pathobiological role of estrogenic androgen metabolites, concentrations of DHEA, Adione, Aenediol, Aanediol, E1, and E2 in pairs of serum and tumor tissue from patients with primary breast cancer were measured by liquid chromatography-tandem mass spectrometry. Cell proliferation assays using Aenediol were performed for four breast cancer cell lines. Serous E2 concentration was extremely low in postmenopausal women; however, a marked increase in tumor tissue was observed in hormone receptor-positive cases. E1 concentration, in contrast, was sustained at a higher level, even in postmenopausal serum, and did not increase in tumor tissue irrespective of the hormone receptor status. Dehydroepiandrosterone was most abundant in all samples, and exhibited a similar pattern as Adione and Aenediol. 5 alpha-Androstane-3 beta, 17 beta-diol was undetectable in most samples. Androstene-3 beta, 17 beta-diol proliferated estrogen receptor-alpha-positive breast cancer cells in the absence of E2. The intratumoral increase of E2, but not E1, in hormone receptor-positive postmenopausal breast cancer tissue, as well as the proliferative role of Aenediol, was elucidated. (Cancer Sci 2011; 102: 1848-1854)

82歳，男性。初診の1年3ヵ月前より左腋窩の皮疹に気付き，近医皮膚科を受診した。真菌症として外用治療を受けるが改善なく，当科へ紹介され受診した。左腋窩に5cm大の紅斑局面，一部びらんを認めた。皮膚生検で乳房外Paget病と診断した。腫瘍辺縁から1cm離し，脂肪織深層で切除，メッシュ植皮術を施行した。腋窩リンパ節は触知しなかった。術後1年2ヵ月で左腋窩リンパ節の腫脹が出現し，リンパ節生検で腋窩リンパ節転移と診断した。後日，左腋窩リンパ節郭清術を施行した。全身検索では他臓器に転移を認めなかった。術後補助療法として放射線計50Gyとweekly taxotere 40mg/回，4クール投与を行った。リンパ節郭清術後10ヵ月で腫瘍の再発，転移を認めていない。また術後補助療法による重篤な副作用を認めていない。

Introduction Peripherally localized aromatase, which converts circulating androgens into estrogens, is important in the pathogenesis of postmenopausal breast carcinomas. We have previously shown that aromatase mRNA levels are higher in elderly breast carcinomas (EldCa) than breast carcinomas of the control group (ContCa) or normal breast tissues. Aromatase expression has been reported to be regulated through the alternative use of multiple exons 1 (exons 1a-1f and so on); however, the preferential usage of exons 1 in elderly breast tissue has never been systematically examined. In order to properly treat and protect against EldCa, the regulation mechanism of aromatase expression in elderly breast tissues should be elucidated. The aim of the present study is to elucidate whether there are any specific patterns in use of multiple exons 1 in elderly breast tissue. Methods Usage of multiple exons 1 of the aromatase gene and mRNA levels of aromatase were examined by reverse transcription-polymerase chain reaction analysis in breast tissues of 38 elderly patients with breast cancer (age 80-99), and the results were compared with those in 35 patients of the control group (age 37-70). One-factor analysis of variance and the Scheffe test were used for the comparison of aromatase mRNA levels. Patterns of preferential utilization of multiple exons 1 of the aromatase gene were compared by chi(2) test for independence or Fisher exact test for independence using a contingency table. Results Exon 1d was utilized much more frequently in elderly tissue than in the control group irrespective of cancerous or normal tissue (EldCa, 36/38, 95% versus ContCa, 7/35, 20%, P < 0.0001; normal tissue of the elderly, EldNorm, 30/34, 88% versus normal tissue of controls, ContNorm, 2/29, 7%, P < 0.0001). Twenty EldCa (53%) and 12 EldNorm (35%) used both exons 1c and 1d; however, their dominance was reversed (EldCa, all 1d > 1c; EldNorm, all 1c > 1d). Conclusions Elderly breast tissues exhibited specific patterns in use of multiple exons 1, which at least partly explained the higher aromatase levels in EldCa. The mechanisms of how these specific patterns occur during aging and carcinogenesis should be further examined.