Risk of Breast Cancer in Japanese Women with Benign Breast Disease

Abstract

To investigate the risk of breast cancer development in women with benign breast disease (BBD), 387 screen-detected BBD women and 1,489 normal women, taken from participants in the breast cancer screening program during 1978-1986, were followed through 1991. While 2,811 personyears in the BBD group and 11,018 person-years in the normal group were accumulated, 5 women in the BBD group and 6 women in the normal group developed breast cancer. Using the MantelHaenszel method, relative risks (RR) were estimated for all women with BBD and women in some BBD types. Significantly elevated risk of breast cancer was observed in all women with BBD (RR = = = =3.26, 95% confidence interval (CI) 1.08-9.83). Women with proliferative BBD were at high risk of breast cancer (RR = = = =8.48, 95%CI 2.99-24.10), but no increased risk was observed for women with non-proliferative BBD (RR = = = =0.93, 95%CI 0.11-7.66). These results are consistent with those in high-risk countries for breast cancer. In the management of women with BBD, histopathological diagnosis of the breast lesion is essential and women with proliferative BBD should be followed up carefully. Key words:Benign breast disease -Breast cancer risk -Cancer registry -Retrospective cohort study -Screening It has been reported that a history of benign breast disease (BBD) increases breast cancer risk, [1][2][3][4] but recent studies have shown that the risks for subsequent breast cancer in BBD patients who have had a biopsy are different among different histopathological types. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] While the histopathological classification systems used in these studies were not the same, there was a consistent finding that atypical hyperplasia (AH) presents high risk for the development of breast cancer. 20) Although Japan is one of the countries with low risk for breast cancer, the incidence rate of female breast cancer is gradually increasing. 21) A number of epidemiological studies of breast cancer have recently been conducted and the characteristics of Japanese women with breast cancer have been clarified. 3,4,[22][23][24][25] However, there have been few studies on the prognosis in BBD patients 18) and the relation of BBD to breast cancer risk is unclear in Japan.We have reported similarities of background characteristics between proliferative BBD (including AH) and breast cancer, using data obtained from breast cancer screening participants.26) The present study was conducted in order to evaluate the subsequent breast cancer risk among the BBD patients described in the previous report. Accumulations and comparisons of data among countries with different risk for breast cancer seem necessary for elucidating the association of BBD lesions with breast cancer risk. This study provides additional data from a low-risk country for breast cancer. MATERIALS AND METHODSStudy subjects and histopathological classification This study was conducted by using data obtained from breast cancer screening participants during 1978-1986. The breast cancer...

Dietary and other risk factors in women having fibrocystic breast conditions with and without concurrent breast cancer: A nested case‐control study in Shanghai, China

“…In both incidences, the relative risks are probably underestimated because prior breast lumps that developed after the baseline questionnaire was administered were not included. These findings are consistent with the results from prospective studies [1][2][3][4][5][6][7][8] showing risk of breast cancer to be greater and more consistently observed in women with proliferative than non-proliferative benign breast conditions, and they are supportive of the hypothesis that breast carcinomas may arise from benign proliferative epithelium. Conversely, we observed about a 3-fold increased risk of fibrocystic breast conditions alone and about a 6-fold increased risk of breast cancer in women with a first-degree relative with breast cancer; and these associations were observed both in women with proliferative and non-proliferative benign breast conditions.…”

“…1 Although nonproliferative breast conditions do not seem to be associated with increased risk of breast cancer, proliferative fibrocystic breast conditions without and with atypia have been associated with 2-fold and 4-fold increased risks of breast cancer, respectively. [2][3][4][5][6][7][8] Most women who are diagnosed with proliferative fibrocystic breast conditions do not develop breast cancer, however, suggesting the presence of risk factors necessary for progression.…”

The Effect of Supraphysiologic Levels of Iodine on Patients with Cyclic Mastalgia

“…In contrast to prior suggestions, the concept proposed here is potentially relevant only to nonlactating women whose mammary tissue may be capable of concentrating iodine due to a subtle imbalance in PRL control. The use of iodine in a patient population with cyclic mastalgia and clinically significant fibrocystic breast tissue could provide clinicians with a new tool to address the question of whether this combination of symptoms predisposes certain women to breast cancer as some believe (47–49).…”

Family history of breast cancer, age and benign breast disease

“…Women with a history of benign breast disease (BBD) are at increased risk of developing breast cancer 1. Although nonproliferative disease does not appear to be associated with increased risk,2, 3 proliferative disease without atypia and proliferative disease with atypia have been associated with approximately a 1.5‐fold and a 4‐fold increased risk of cancer, respectively 3, 4, 5. This risk appears to be approximately equal for cancer developing in the same breast as the BBD or in the opposite breast6, 7, 8 and it is unclear whether the BBD is a precursor lesion or simply a marker for a generalized increased risk of cancer.…”