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

Abstract

Background With life span extending, breast cancer (BC) survivors may face the possibility of developing second primary cancer (SPC) and considerably shorten survivorship. However, little is known about multiple primary cancer (MPC) patients with nonmetastatic breast cancer as a first primary malignancy (BCFPM). Methods Here, we retrospectively analyzed data on cancer survivors with BCFPM diagnosed between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. The prognostic factors for breast cancer‐specific survival (BCSS) were ascertained by the stepwise regression analysis and a competing risk model, and were integrated to the establishment of prognostic nomogram, of which the accuracy was measured by the calibration curve and the concordance index (C‐index). Results In total, 8616 patients were identified with 4.6% of 3‐year breast cancer‐ specific death (BCSD) and 8.6% of 5‐year BCSD. The most common SPC among BCFPM patients were female BC and lung cancer. Besides, the median latency time between BC and SPC was 22 months. At a ratio of 7:3, all patients were randomly categorized into a training cohort (n = 6032) and a validation cohort (n = 2584). By a proportional subdistribution hazards regression analysis, the following factors were considered to own independent prognostic abilities of BCSS: subtypes, grade, T classification, N classification, radiation, and sites of SPC. The nomogram could accurately predict 3‐year and 5‐year breast cancer‐associated survival of BCFPM patients with high internal and external validated C‐index, 0.715 (95% CI, 0.691–0.739), and 0.683 (95% CI, 0.642–0.724), respectively. Conclusions BC survivors remained a high risk of developing SPC and considerably shortened survival time. In this study, a favorable nomogram was constructed to as a prediction model for 3‐year and 5‐year BCSS of BCFPM patients, largely intending to prolong the life of these patients by assisting clinicians to make individualized follow‐up plans.

Relationship between metastasis and second primary cancers in women with breast cancer

“…The risk of second primary BC was even lower in NMBC patients. However, our results contradict previous studies which reported an increased risk of SPCs in NMBC patients ( 17 , 18 ). It is important to note that previous studies failed to incorporate the peculiarities of regional lymph nodes MBC patients and were classified in the same “non-metastatic” category.…”

Development and validation of nomograms to predict the survival probability and occurrence of a second primary malignancy of male breast cancer patients: a population-based analysis

“…A similar study was published by Bao et al. on female breast cancer patients ( 31 ). Mellemkjær et al.…”

Risk of second primary cancer among breast cancer patients: A systematic review and meta-analysis

“…The descriptive epidemiology of second primary cancer among survivors at 5, 10, and 15 years is reported to be 3.6%, 8.2%, and 13.9%, respectively ( 13 ), and patients less than 50 years of age (also premenopausal ages) are at a higher risk of developing second cancer ( 10 , 12 ). Several population-based cancer registry studies have assessed the risk of second primary cancers among women diagnosed with primary breast cancer compared with the general population ( 10 , 12 , 14 – 18 ). Some studies have also examined the risk of developing second cancer based on the type of treatment ( 19 – 24 ), age difference ( 25 – 27 ), and family history ( 27 – 29 ).…”