Clinical Characteristics and Prognosis Associated with Multiple Primary Cancers in Breast Cancer Patients

Abstract

PurposeBreast cancer is one of the most common malignancies worldwide and the second most common cancer among Korean women. The prognosis of breast cancer is poor in patients with other primary cancers. However, there have been few clinical studies regarding this issue. Therefore, we analyzed the characteristics and prognosis of patients with breast cancer with multiple primary cancers (MPCs).MethodsData from the Korean Breast Cancer Society Registry were analyzed. Data from enrolled patients who underwent surgery for breast cancer were analyzed for differences in prognosis dependent on the presence of MPCs, and which MPC characteristics affected their prognosis.ResultsAmong the 41,841 patients analyzed, 913 patients were found to have MPCs, accounting for 950 total MPCs. There was a significant difference in survival rates between the breast cancer only group and the MPC group. The 5-year survival rates were 93.6% and 86.7% and the 10-year survival rates were 87.5% and 70.4%, respectively. Among the 913 patients with MPCs, patients with two or more MPCs had significantly worse prognoses than patients with a single MPC. With respect to the time interval between breast cancer and MPC occurrence, patients with a 5-year or greater interval had significantly better prognoses than patients with less than 1 year between occurrences. Among MPCs, thyroid cancer was the most common primary cancer. However, this type was not related to the prognosis of breast cancer. Gynecologic cancer, colorectal cancer, upper gastrointestinal cancer, and lung cancer were related to breast cancer prognosis.ConclusionMPCs were a poor prognostic factor for patients with breast cancer. Two or more MPCs and a shorter time interval between occurrences were worse prognostic factors. Although MPCs were a poor prognostic factor, thyroid cancer did not affect the prognosis of patients with breast cancer.

Nonmetastatic breast cancer patients subsequently developing second primary malignancy: A population‐based study

“…As similar to above results, a large-scale data analysis in Korea showed that thyroid cancer finally proved to be the most common MPC for patients with prior BC, accounting for 48.5%, followed by gynecologic cancer, upper gastrointestinal cancer, colorectal cancer, and lung cancer. 6 Those findings might remind clinicians that surveillance for female breast, lung, thyroid, and other common sites would also be preferable after the treatment of initial BC. In addition, we further explored the time interval between two primary cancers and revealed that median interval was 22 months, which partly address a matter of how often to follow-up after BC diagnosis.…”

“…Nonetheless, there are few researches on MPC, especially for MPC involving BC. In addition, it was evidence from large‐scale data that the clinical prognosis of BC survivors with MPC is not optimistic 6,7 …”

“…In addition, it was evidence from large-scale data that the clinical prognosis of BC survivors with MPC is not optimistic. 6,7 At present, TNM staging system, the most extensively used approach to evaluate survival outcomes, is not suitable for these patients who are related to special biological characteristics and complicated prognosis judgement. Thus, a dedicated clinical prognostic model for patients with MPC involving BC is urgently needed.…”

Diagnosis and Individualized Treatment of Three Primary Malignant Tumors: A Case Report

“…Specifically, studies have found that the prognosis of patients with thyroid cancer after breast cancer is not different from that of patients with only breast cancer. 20 In contrast, while Zhang demonstrate that MPMT patients have a worse prognosis than patients with breast cancer alone, which may be the result of differences between the analyzed groups, 21 Hamza report no significant difference in overall survival or PFS between patients with only malignant glioma and those with simultaneous non-central nervous system primary tumors. 22 Nevertheless, many studies have also demonstrated that prognosis in concurrent malignancies is worse than that of metachronous malignancies, 20 , 23 and as there are only a few studies on the prognosis in MPMT, more relevant studies are needed for meaningful statistical analysis.…”

High Incidence and Prevalence of Papillary Thyroid Cancer in Breast Cancer Patients

“…Many studies have described an increased risk of thyroid cancer among breast cancer patients (2)(3)(4)(5)(6). Thyroid cancer may be detected during the follow-up of breast cancer patients and vice versa.…”