Influence of family history on penetrance of hereditary cancers in a population setting

High expression of PPP1CC promotes NHEJ-mediated DNA repair leading to radioresistance and poor prognosis in nasopharyngeal carcinoma

Protein phosphatase 1 catalytic subunit gamma (PPP1CC) promotes DNA repair and tumor development and progression, however, its underlying mechanisms remain unclear. This study investigated the molecular mechanism of PPP1CC's involvement in DNA repair and the potential clinical implications. High expression of PPP1CC was significantly correlated with radioresistance and poor prognosis in human nasopharyngeal carcinoma (NPC) patients. The mechanistic study revealed that PPP1CC bound to Ku70/Ku80 heterodimers and activated DNA-PKcs by promoting DNA-PK holoenzyme formation, which enhanced nonhomologous end junction (NHEJ) -mediated DNA repair and led to radioresistance. Importantly, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) interacted with PPP1CC to enhance its stability by removing the K48-linked polyubiquitin chain at Lys234 to prevent PPP1CC degradation. Therefore, BRCC3 helped the overexpressed PPP1CC to maintain its high protein level, thereby sustaining the elevation of DNA repair capacity and radioresistance. Our study identified the molecular mechanism by which PPP1CC promotes NHEJ-mediated DNA repair and radioresistance, suggesting that the BRCC3-PPP1CC-Ku70 axis is a potential therapeutic target to improve the efficacy of radiotherapy.

Impact of bladder cancer family history on the prognosis of patients with non-muscle invasive bladder cancer treated with Bacillus Calmette-Guerin (BCG)

BACKGROUND

To evaluate the impact of having first-degree relatives (FDR) with bladder cancer (BC) among non-muscle invasive bladder cancer (NMIBC) patients treated with Bacillus Calmette - Guérin (BCG) on their oncological outcomes.

METHODS

The National Phase II BCG/Interferon (IFN) trial database from 125 sites in the U.S.A. (1999-2001) and multi-institutional databases from France (FR) and Lebanon (LB) (2000-2021) were queried for NMIBC patients treated with BCG. Cox regression models were used to evaluate the effect of BC family history on tumor recurrence and progression in their relatives.

RESULTS

There were 867 patients in the U.S.A. cohort and 1232 patients in the FR/LB cohort. Almost 8% of patients in both cohorts had FDR with BC. Patients in the FR/LB cohort were more likely to have carcinoma in situ tumors (CIS) (41% vs. 24%, p < 0.01). Having FDR with BC was not significantly associated with tumor recurrence or progression in the U.S.A. cohort. Conversely, on multivariable analysis FDR history was significantly associated with a 2.10 times increased risk of recurrence (p < 0.01) and a 3.01 times increased risk of progression (p < 0.01) in the FR/LB cohort.

CONCLUSION

A family history of BC could have an important impact on the response to BCG.

Association between Family History of Breast Cancer and Breast Density in Saudi Premenopausal Women Participating in Mammography Screening

BACKGROUND

Mammographic density and family history of breast cancer (FHBC) are well-established independent factors affecting breast cancer risk; however, the association between these two risk factors in premenopausal-screened women remains unclear. The aim of this study is to investigate the relationship between mammographic density and FHBC among Saudi premenopausal-screened women.

METHODS

A total of 446 eligible participants were included in the study. Mammographic density was assessed qualitatively using the Breast Imaging Reporting and Data System (BIRADS 4th edition). Logistic regression models were built to investigate the relationship between mammographic density and FHBC.

RESULTS

Women with a family history of breast cancer demonstrated an 87% greater chance of having dense tissue than women without a family history of breast cancer (95% CI: 1.14-3.08; p = 0.01). Having a positive family history for breast cancer in mothers was significantly associated with dense tissue (adjusted odds ratio (OR): 5.6; 95% CI: 1.3-24.1; p = 0.02).

CONCLUSION

Dense breast tissue in Saudi premenopausal women undergoing screening may be linked to FHBC. If this conclusion is replicated in larger studies, then breast cancer risk prediction models must carefully consider these breast cancer risk factors.