Associations of reproductive factors with breast cancer prognosis and the modifying effects of menopausal status

A comparative analysis of clinicopathological features and survival between pre and postmenopausal breast cancer from an Indian cohort

Breast cancer (BC) among premenopausal women is an aggressive disease associated with poor outcome despite intensive treatment. Higher burden is observed in southeast Asian countries attributed to younger population structure. We compared the reproductive and clinicopathological characteristics, distribution of subtypes and survival between pre and postmenopausal women from a retrospective cohort of BC patients with median follow up over 6 years to examine the differences. In our cohort of 446 BC patients, 162/446 (36.3%) were premenopausal. Parity and age at last childbirth were significantly different between pre and postmenopausal women. Premenopausal BC had a higher proportion of HER2 amplified and triple negative breast cancer (TNBC) tumors (p = 0.012). Stratified analysis by molecular subtypes showed TNBC had significantly better disease free (DFS) and overall survival (OS) among premenopausal group (mean survival, pre vs. post, DFS = 79.2 vs. 54.0 months, OS = 72.5 vs. 49.5 months, p = 0.002 for both). Analysis on external datasets (SCAN-B, METABRIC) confirmed this finding for overall survival. Our data confirmed the previously observed association of clinical and pathological features between pre and postmenopausal BC. Exploration of better survival among premenopausal TNBC tumors is warranted in larger cohorts with long term follow up.

Multivariate analysis of independent roles of socioeconomic status, occupational physical activity, reproductive factors, and postmenopausal hormonal therapy in risk of breast cancer

PURPOSE

This case-control study assesses the independent roles of reproductive history, postmenopausal hormonal therapy (HT), socioeconomic status (SES), and occupational physical activity on the risk of breast cancer (BC).

METHODS

Odds ratios (OR) were estimated from conditional logistic multivariate regression model in a data set of 19,253 Finnish women diagnosed with BC between 1994 and 2013 and 96,265 age-matched population controls.

RESULTS

Both pre- and postmenopausal white-collar workers had significantly increased risk of ductal and lobular BC as compared to manual workers. Moderate occupational physical activity reduced risk of lobular BC by 14%. There was a transient increase in the risk of BC observed after each birth followed by a protective effect starting some years after the delivery. As the number of children increased, the short-term excess risk was lower and protective effect was observed earlier. Continuous estrogen-progestin therapy (EPT) significantly increased the risk of both ductal and lobular BC and the magnitude of risk was directly proportional to duration of use (OR for 5+ years of use 2.26, 95% confidence interval 2.12-2.42). Monthly EPT for 5+ years increased the risk (OR 1.32, 95% CI 1.20-1.45). Users of estradiol plus levonorgestrel intrauterine system devices showed ORs of 1.56 (95% CI 1.45-1.69) and 2.18 (95% CI 1.81-2.64) for ductal and lobular BC, respectively.

CONCLUSION

This study concludes that pregnancy has a dual effect on BC risk, with a transient increase in risk followed by a long-term protective effect. The SES and HT have a large effect on BC risk while occupational physical activity has only a small independent effect.

Clinical and pathological features and risk factors for primary breast cancer patients

BACKGROUND

Breast cancer is the most common malignancy in women all around the world. According to the latest statistics in 2018, there were more than 2.08 million new breast cancer cases all around the world and more than 620000 deaths; the proportion of breast cancer deaths in women with cancer is 15%. By studying age, clinicopathological characteristics and molecular classification, age at menarche, age at birth, number of births, number of miscarriages, lactation time, surgical history of benign breast lesions, history of gynecological diseases, and other factors, we retrospectively summarized and compared the disease history of patients with primary breast cancer and patients with benign thyroid tumors admitted to our hospital in the past 10 years to explore the clinicopathological characteristics and risk factors for primary breast cancer.

AIM

To investigate the clinical and pathological features and risk factors for primary breast cancer treated at our center in order to provide a reference for the prevention and treatment of breast cancer in the Zhuhai-Macao region.

METHODS

Through a retrospective case-control study, 149 patients with primary breast cancer diagnosed and treated at Zhuhai Hospital of Guangdong Provincial Hospital of Traditional Chinese Medicine from January 2013 to March 2020 were included as a case group, and 165 patients with benign breast tumors diagnosed and treated from January 2019 to March 2020 were included as a control group. The data collected included age, age at menarche, age at first birth, number of births, number of miscarriages, lactation time, history of surgery for benign breast lesions, history of familial malignant tumors, history of gynecological diseases, history of thyroid diseases, and the tumor characteristics of the patients in the case group including pathological diagnosis, pathological type, tumor size, lymph node metastasis, distant metastasis, stage, and molecular classification, among others. In the case group, the chi-square test was used to analyze the clinical and pathological features of patients in three age groups (< 40, 40-59, and ≥ 60 years). A multifactor logistic regression analysis was used to analyze correlations between the two groups.

RESULTS

Among 149 patients with primary breast cancer, the average age was 48.20 ± 12.06 years, and the proportion of patients at 40-59 years old was the highest, accounting for 61.8% of cases. The molecular type was mainly luminal B type, accounting for 69.2% of cases, and at the time of diagnosis, the tumor stage was mainly stage I/II, accounting for 62.4% of cases. There were no statistically significant differences in the distributions of tumor location, pathological type, tumor size, lymph node metastasis, stage, or molecular classification among the three age groups (< 40, 40-59, and ≥ 60 years) (P ≥ 0.05). The differences in the distribution of distant metastasis among the three age groups (< 40, 40-59, and ≥ 60 years) were statistically significant (P < 0.01). The differences in lactation time, history of familial malignant tumors, history of gynecological diseases, and history of thyroid diseases between the two groups were not statistically significant (P ≥ 0.05). The differences in age at disease diagnosis, age at menarche, and history of surgery for benign breast lesions were statistically significant (P < 0.01). The difference in age at first birth was also statistically significant (P < 0.05).

CONCLUSION

The highest incidence of breast cancer in the Zhuhai-Macao region is present among women aged 40-59 years. There is a larger proportion of stage I/II patients, and the luminal B type is the most common molecular subtype. Distant metastasis occurs mainly in the ≥ 60-year-old group at the first diagnosis; increased age, late age at menarche, and late age at first birth may be risk factors for primary breast cancer, and a history of surgery for benign breast lesions may be a protective factor for primary breast cancer.

Associations of reproductive factors with breast cancer prognosis and the modifying effects of menopausal status

Reproductive factors associated with breast cancer risk may also affect the prognosis. This study aimed to evaluate the associations of multiple reproductive factors with breast cancer prognosis and the modifying effects of menopausal status. We obtained data from 3805 breast cancer patients recruited between October 2008 and June 2016 in Guangzhou. The subjects were followed up until 30 June 2018. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using multivariate Cox models to estimate the associations. It was found that there were U‐shaped patterns for the associations of age at first birth and durations from first/last birth to diagnosis with breast cancer prognosis. The adverse effects of old age at first birth [>30 years vs 23‐30 years, HR (95% CI): 1.59 (1.01‐2.50)] and long intervals from first [≥20 years vs 10‐19 years, HR (95% CI): 1.55 (1.07‐2.27)] or last [≥20 years vs 10‐19 years, HR (95% CI): 1.63 (1.08‐2.46)] birth to diagnosis on progression‐free survival (PFS) were significantly more pronounced among premenopausal women. Additionally, long interval (>5 years) between first and second birth was associated with a better PFS [HR (95% CI): 0.64 (0.42‐0.97)]. These results suggested that age at first birth, durations from first/last birth to diagnosis, and intervals between first and second birth should be taken into account when following the patients and assessing the prognosis of breast cancer, particularly for premenopausal patients. These findings would also have implications for further insight into the mechanisms of breast cancer development.