Risk of colorectal adenomas in women with prior breast cancer

Bidirectional Mendelian randomization analysis investigating the genetic association between primary breast cancer and colorectal cancer

Purpose

With the advancement in early diagnosis and treatment, the prognosis for individuals diagnosed with breast cancer (BC) has improved significantly. The prognosis of primary breast cancer (PBC) survivors can be significantly influenced by the occurrence of colorectal cancer (CRC) as a secondary primary cancer (SPC). The objective of this study is to explore the possible genetic association between PBC and CRC, aiming to lay a groundwork for the development of preventive strategies against SPC-CRC following BC surgery.

Methods

We employed a bidirectional two-sample Mendelian randomization (MR) approach to thoroughly examine genetic instrumental variables (IVs) derived from genome-wide association studies (GWAS) conducted on PBC and CRC. And applied inverse variance weighted (IVW) and multiple other MR methods (weighted median, simple median, MR-PRESSO and MR-RAPS) to evaluate the association between the two cancers (PBC and CRC) at genetic level. Furthermore, the robustness of the findings was further confirmed through the utilization of the genetic risk score (GRS) method in a secondary analysis.

Results

Forward MR analysis, a total of 179 BC genetic IVs, 25 estrogen receptor-negative (ER-) genetic IVs and 135 ER-positive (ER+) genetic IVs were screened. Reverse MR analysis, 179 genetic IVs of CRC, 25 genetic IVs of colon cancer, 135 genetic IVs of rectal cancer, 25 genetic IVs of left colon cancer and 135 genetic IVs of right colon cancer were screened. IVW and other MR methods found no significant genetic association between PBC and CRC (P > 0.05). Subgroup analysis also showed that ER- BC and ER+ BC were not correlated with the occurrence of CRC (P > 0.05). The findings of the secondary analysis using GRS were consistent with those obtained from the primary analysis, thereby confirming the robustness and reliability of this study.

Conclusions

Our findings do not provide any evidence supporting the association between PBC and CRC at the genetic level. Further large-scale prospective studies are warranted to replicate our findings.

Incidence of other cancer diagnoses in women with breast cancer: a retrospective cohort study with 42,248 women

PURPOSE

The aim of the present study was to determine whether women diagnosed with breast cancer (BC) have an increased incidence of other cancers, e.g., gastric cancer, lung cancer, skin cancer, and so on, compared to healthy women without a breast cancer diagnosis.

METHODS

This retrospective cohort study was based on data from the Disease Analyzer database (IQVIA) and included adult women with an initial diagnosis of BC documented in one of 1,274 general practices in Germany between January 2000 and December 2018. Women with BC were matched to women without cancer by age, index year, yearly consultation frequency, and co-diagnoses. Univariate Cox regression models were used to study the association between BC and the incidence of other cancer diagnoses.

RESULTS

21,124 women with BC and 21,124 women (mean age: 63 years) without cancer were included. Within 10 years of the index date, 14.3% of women with BC and 10.0% of women without cancer were diagnosed with cancer (p < 0.001). BC was significantly associated with the incidence of other cancer diagnoses (HR: 1.42, p < 0.001). The strongest association was observed for respiratory organ cancer (HR = 1.69, p < 0.001), followed by female genital organ cancer (HR = 1.61, p < 0.001) and cancer of lymphoid and hematopoietic tissue (HR: 1.59, p < 0.001).

CONCLUSION

The results of this study show that women with BC have an increased incidence of another cancer compared to women without cancer. Therefore, it is important to pay particular attention to the development of other malignancies during follow-up in patients with BC. This should be considered especially in patients with a proven genetic mutation.

Clinicopathologic Characteristics and Survival of Patients With Double Primary Malignancies: Breast and Colorectal Cancer

Purpose

This study aimed to investigate the clinicopathologic features and survival in patients with both breast cancer (BrC) and colorectal cancer (CRC).

Methods

Between 1996 and 2019, patients who were diagnosed with both BrC and CRC were evaluated retrospectively. Patients with distant metastasis, palliative resection, and previous cancer histories except for BrCs or CRCs were excluded. Altogether, 105 patients were divided into the B=C group (n=21), B-first group (n=40), and C-first group (n=44) according to the definition of synchronous and metachronous cancers. The clinicopathologic features and overall survival were evaluated.

Results

TNM stages and histologic types were comparable among the 3 groups (P=0.434). The interval of diagnosis was 67.1±40.4 and 59.3±47.2 months in the B- and C-first groups, respectively. The incidence of adjuvant chemotherapy in the B-first group was 57.5%, which was higher than the B=C and C-first groups (P<0.001). The estrogen receptor, progesterone receptor, Ki-67, and HER-2 molecular markers were not significantly different among the groups. The overall survival of the B-first group showed lower survival rates than the C-first group (P=0.039). In the logistic regression, HER-2 status (hazard ratio [HR], 11.9; P=0.032) and lymph node metastasis of CRC (HR, 5.8; P=0.036) were prognostic factors affecting overall survival.

Conclusion

B-first group had poorer survival outcomes than the C-first group in patients with the metachronous BrC and CRC. HER2 positivity and CRC lymph node metastasis may be prognostic factors that affect overall survival in these patients. The findings support that a colorectal cancer screening program should be included during BrC surveillance.

Risk of breast cancer-related death in women with a prior cancer

The overall risk of developing a second primary cancer is increasing. The purpose of this study was to analyze the survival of patients with breast cancer diagnosed after a prior cancer and identify risk factors of breast cancer death in this population. Using the SEER database, we identified 1,310 woman diagnosed with breast cancer between 2010 and 2015 after a prior cancer as the primary cohort. Clinicopathological characteristics were compared using the Student t-test and chi-square test. Fine and Gray’s regression was used to evaluate the effect of treatments on breast cancer death. After propensity score matching (PSM), 9,845 pairs of patients with breast cancer as the prior or second cancer diagnosed between 2010 and 2011 were included as a second cohort. PSM-adjusted Kaplan-Meier and Cox hazards models were used to evaluate the impact of prior cancer on survival. The results showed that survivors of gynecologic cancers (e.g., ovarian cancer) had a higher risk of developing breast cancer than survivors of gastrointestinal and urinary tract cancers. More patients died of breast cancer than of prior urinary cancer (53.3% vs. 40%, P < 0.05) and melanoma (66.7% vs. 33.3%, P < 0.05). The ratio of breast cancer deaths to prior cancer deaths was significantly higher in patients with diagnoses interval ≥ 3 years than in those with the interval < 3 years (2.67 vs. 0.69, P < 0.001). Breast cancer-specific survival and overall survival rates were significantly lower in women with breast cancer as the second primary cancer than in those with breast cancer as the prior cancer, especially among hormone receptor-positive women. However, breast cancer treatment decreased the risk of breast cancer -specific death (hazard ratio = 0.695, 95% confidence interval: 0.586–0.725, P < 0.001). Breast cancer patients with prior cancers must be carefully considered for clinical trials.

Patients with breast cancer may be at higher risk of colorectal neoplasia

Background

The risk of colorectal neoplasia in breast cancer survivors is unclear. This study aimed to determine the colonic adenoma detection rate (ADR) in patients with breast cancer.

Methods

We conducted a retrospective study of patients with breast cancer who underwent a colonoscopy between 2000 and 2017. A control group (n=3295), comprising cancer-free patients undergoing their first screening colonoscopy, was used for comparison.

Results

Of 62,820 breast cancer patients, 3304 met the inclusion criteria. The mean age at the time of first colonoscopy was 59 years. ADR was 55%; 1803 patients had adenomas. High-grade dysplasia was evident in 28% of polyps and invasive adenocarcinoma was detected in 172 patients (5%). The median time from breast cancer diagnosis to adenoma detection was 3 years. The ADR was 21% in patients aged <40 years (n=63) and 39% in patients aged 40-50 years (n=314). The ADR was 26% in patients <50 years with a body mass index (BMI) lower than 30 kg/m² or no family history of colorectal cancer. Multivariate logistic regression analysis revealed that the following independent factors were associated with a greater risk of colon adenoma: older age, higher BMI, family history of colorectal cancer, and personal history of breast cancer.

Conclusions

In patients with breast cancer, the ADR was higher than the reported rates for the general population. Screening colonoscopy should be considered soon after breast cancer diagnosis in patients <50 years of age. Further prospective studies investigating our findings are warranted.

Association between breast cancer and the risk of colorectal cancer

BACKGROUND

The literature to date has suggested a potential increase in colorectal cancer (CRC) among patients with breast cancer.

METHODS

We performed a systematic review of the literature and included 37 retrospective cohort studies and 8 case-control studies. The primary aim was to determine the prevalence of CRC. Secondary aims included analysis of adenomatous polyps and analysis of CRC prevalence by age. We calculated pooled prevalence rates and odds ratios (ORs) using random effects models with 95% confidence intervals (CI).

RESULTS

We identified 1,055,917 individuals with breast cancer among whom 9097 cases of CRC were detected. The pooled event rate for CRC was 0.7% (95% CI, 0.6%-0.9%; I²=97%). Four case-control studies reported prevalence of CRC (N=17,873 patients with breast cancer and 70,366 controls), including 46 cases of CRC in the patients with breast cancer, and 272 CRC in the controls (OR, 1.2; 95% CI, 0.4%-3.7%; P = .7). Six studies reported prevalence of advanced adenomas in patients with breast cancer (N=1087) compared with controls (N=1356) with 62 cases of advanced adenomas in patients compared with 47 in the controls (OR, 1.5; 95% CI, 0.97-2.2; P = .07). In patients with breast cancer <50 years old (4 studies, N=64,706), the pooled OR was increased (OR, 2.5; 95% CI, 1.7-3.5; P =.001). In 3 studies of women <45 years old (N=92,594), the risk was increased (OR, 2.3; 95% CI, 1.7-2.6; P < .001).

CONCLUSIONS

Patients with breast cancer should not undergo CRC screening at intervals different from the general population. In patients with breast cancer <50 years old, CRC screening should be considered at age 45 years.