Risks of second non-breast primaries following breast cancer in women: a systematic review and meta-analysis

Incidence and Characteristics of Multiple Primary Cancers: A 20-Year Retrospective Study of a Single Cancer Center in Korea

Rising cancer survival rates have led to an increased risk of multiple primary cancers (MPCs). Data on MPCs in South Korea are limited. This study aimed to address incidence and clinical characteristics of MPCs in a single cancer center in Korea during a 20-year period. We retrospectively analyzed 96,174 cancer patients at the Korea Cancer Center Hospital between 2003 and 2022, identifying 2167 patients with metachronous MPCs based on Surveillance, Epidemiology, and End Results SEER criteria. We categorized patients by cancer type (15 major solid cancer groups and 3 major hematologic cancer groups), including pathological diagnosis, assessed latency periods, and relative risks (RRs) for developing MPCs. The overall MPC incidence was 2.3%. Breast cancer (15.7%) was the most common primary cancer, and lung cancer (15.2%) was the most frequent second primary cancer. The median latency period for second primary cancers was 4.1 years. Decreasing latency periods for third and fourth primary cancers were observed (2.1 years and 1.6 years, respectively). Most cancers maintained their dominant pathological type despite notable changes in the prevalence of specific pathologies for certain types of second primaries. Lymphoma showed the highest RR (2.1) for developing MPCs. Significant associations were found between specific primary and subsequent cancers, including breast-ovary, thyroid-breast, stomach-pancreas, colorectal-head and neck, lung-prostate, and lymphoma-myeloid neoplasms. These findings contribute to a better understanding of MPC occurrence. They can inform future research on their etiology and development of improved management strategies.

Risks of second primary cancers among 584,965 female and male breast cancer survivors in England: a 25-year retrospective cohort study

Background

Second primary cancers (SPCs) after breast cancer (BC) present an increasing public health burden, with little existing research on socio-demographic, tumour, and treatment effects. We addressed this in the largest BC survivor cohort to date, using a novel linkage of National Disease Registration Service datasets.

Methods

The cohort included 581,403 female and 3562 male BC survivors diagnosed between 1995 and 2019. We estimated standardized incidence ratios (SIRs) for combined and site-specific SPCs using incidences for England, overall and by age at BC and socioeconomic status. We estimated incidences and Kaplan-Meier cumulative risks stratified by age at BC, and assessed risk variation by socio-demographic, tumour, and treatment characteristics using Cox regression.

Findings

Both genders were at elevated contralateral breast (SIR: 2.02 (95% CI: 1.99-2.06) females; 55.4 (35.5-82.4) males) and non-breast (1.10 (1.09-1.11) females, 1.10 (1.00-1.20) males) SPC risks. Non-breast SPC risks were higher for females younger at BC diagnosis (SIR: 1.34 (1.31-1.38) <50 y, 1.07 (1.06-1.09) ≥50 y) and more socioeconomically deprived (SIR: 1.00 (0.98-1.02) least deprived quintile, 1.34 (1.30-1.37) most).

Interpretation

Enhanced SPC surveillance may benefit BC survivors, although specific recommendations require more detailed multifactorial risk and cost-benefit analyses. The associations between deprivation and SPC risks could provide clinical management insights.

Funding

CRUK Catalyst Award CanGene-CanVar (C61296/A27223). Cancer Research UK grant: PPRPGM-Nov 20∖100,002. This work was supported by core funding from the NIHR Cambridge Biomedical Research Centre (NIHR203312)]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

Value of 18F-FDG PET/CT in breast cancer with second primary malignancies

PURPOSE

To investigate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in breast cancer (BC) with second primary malignancies (SPMs).

MATERIALS AND METHODS

149 BC patients (149/1419, 10.5 %) ultimately diagnosed with SPMs were included in the study. The following data were evaluated: age, location, the treatment of the first BC, the interval between the first BC and SPMs, the maximum diameter of SPMs, the maximum standardized uptake value (SUVmax) of SPMs, and SPMs metastases. The overall survival (OS) and progression-free survival (PFS) of follow-up patients were analyzed. The diagnostic efficiency of 18F-FDG PET/CT for SPMs and consistency with the pathological findings were calculated.

RESULTS

The most common SPMs of BC was lung cancer (81/149, 54.4 %), particularly early-stage lung adenocarcinoma. There were the shorter maximum diameter of SPMs, the lower SUVmax of SPMs, and the fewer SPMs metastases in the lung cancer group than non-lung cancer group (P<0.001). The OS and PFS of the follow-up patients in the lung cancer group were longer than non-lung cancer group (P<0.001). The SPMs metastases was independent prognostic indicator of OS. The pathological grouping and the SPMs metastases were independent prognostic indicators of PFS. 18F-FDG PET/CT efficacy in diagnosing SPMs in BC patients was high. Compared with the pathological findings, the consistency was good (P = 0.010).

CONCLUSION

Applying 18F-FDG PET/CT in BC patients might be helpful in detecting SPMs and partially predicting patient prognosis, in addition to its primary function in the diagnosis and staging of BC.

Second primary cancers among females with a first primary breast cancer: a population-based study in Northern Portugal

PURPOSE

To estimate the incidence rate of second primary cancers (SPCs) and the cumulative incidence of metachronous [diagnosed > 2 months after a first primary cancer (FPC)] SPCs in patients with a breast FPC, and to compare the incidence of SPC [overall, synchronous (≤ 2 months of the FPC) and metachronous] with that expected in the general female population.

METHODS

A cohort of patients with a breast FPC from the North Region Cancer Registry of Portugal, diagnosed in 2000-2010 (n = 15,981), was followed to 31 December 2015 for synchronous and metachronous SPCs. Cumulative incidence of metachronous SPCs considering death as a competing event, and incidence rates and standardized incidence ratios of SPCs were estimated.

RESULTS

The diagnosis of an SPC occurred in 1229 (7.7%) of patients with a breast FPC. SPCs occurred mainly in the breast, followed by digestive organs, lung, thyroid, and female genital organs. Globally, patients with a breast FPC had a higher incidence for all types of cancer compared to the general female population, and in particular for cancers of the breast, stomach, colon, lung, lymphoma, uterus, and ovary. The 10-year cumulative incidence of metachronous SPCs following a breast FPC was 6.6% and the corresponding 10-year cumulative mortality was 26.2%.

CONCLUSION

In Portugal, patients with a breast FPC have a higher incidence of cancer compared to the general female population, highlighting important aspects of care, surveillance, and counselling among this growing number of patients.