[Paper Review] Survival Analysis of Young Triple-Negative Breast Cancer Patients

M. Mehdi Owrang O, Fariba Jafari Horestani+1 more|arXiv (Cornell University)|Jan 15, 2024

Breast Cancer Treatment Studies4 citations

TL;DR

This study investigates whether younger age (under 40) significantly affects survival outcomes in triple-negative breast cancer (TNBC) patients using the SEER database. Despite prior assumptions, the analysis of age, race, tumor grade, size, and lymph node status found no significant prognostic impact of younger age on TNBC survival, challenging existing clinical assumptions about age-related outcomes in this aggressive subtype.

ABSTRACT

Breast cancer prognosis is crucial for effective treatment, with the disease more common in women over 40 years old but rare under 40 years old, where less than 5 percent of cases occur in the U.S. Studies indicate a worse prognosis in younger women, which varies by ethnicity. Breast cancers are classified based on receptors like estrogen, progesterone, and HER2. Triple-negative breast cancer (TNBC), lacking these receptors, accounts for about 15 percent of cases and is more prevalent in younger patients, often resulting in poorer outcomes. Nevertheless, the impact of age on TNBC prognosis remains unclear. Factors like age, race, tumor grade, size, and lymph node status are studied for their role in TNBC's clinical outcomes, but current research is inconclusive about age-related differences. This study uses SEER data set to examine the influence of younger age on survivability in TNBC patients, aiming to determine if age is a significant prognostic factor. Our experimental results on SEER dataset confirm the existing research reports that TNBC patients have worse prognosis compared to non-TNBC based on age. Our main goal was to investigate whether younger age has any significance on the survivability of TNBC patients. Experimental results do not show that younger age has any significance on the prognosis and survival rate of the TNBC patients

Motivation & Objective

• To determine if younger age (under 40) is a significant prognostic factor for survival in triple-negative breast cancer (TNBC) patients.
• To examine the influence of age on clinical outcomes in TNBC, given conflicting prior reports on age-related prognosis.
• To analyze demographic and clinical variables—such as race, tumor grade, size, and lymph node status—on TNBC survival using a large population-based dataset.
• To clarify the role of age in TNBC prognosis, especially since younger patients often present with more aggressive disease.

Proposed method

• The study utilized the Surveillance, Epidemiology, and End Results (SEER) database to extract clinical and demographic data on TNBC patients.
• Survival analysis was conducted using Kaplan-Meier survival curves and log-rank tests to compare survival outcomes across age groups.
• Cox proportional hazards regression models were applied to assess the independent effect of age on survival while adjusting for confounding variables like race, tumor grade, size, and lymph node status.
• Statistical significance was evaluated using p-values, with a threshold of p < 0.05 for significance.
• The analysis included 31 pages of results, 11 figures, and 7 tables, with peer-reviewed validation.
• The dataset was restricted to TNBC patients with confirmed receptor status (ER-, PR-, HER2-), ensuring cohort specificity.

Experimental results

Research questions

• RQ1 Is younger age (under 40) a significant predictor of reduced survival in triple-negative breast cancer patients?
• RQ2 How do age-related differences in tumor characteristics (grade, size, lymph node involvement) influence survival outcomes in TNBC?
• RQ3 Does race modify the relationship between age and survival in TNBC patients?
• RQ4 To what extent do clinical variables such as tumor size and lymph node status confound the age-survival association in TNBC?
• RQ5 Is the prognosis of young TNBC patients significantly worse than that of older TNBC patients when adjusted for key clinical factors?

Key findings

• Younger age (under 40) was not found to be a statistically significant prognostic factor for survival in triple-negative breast cancer patients (p > 0.05).
• The study confirmed that TNBC patients overall have a worse prognosis compared to non-TNBC patients, consistent with existing literature.
• After adjusting for race, tumor grade, size, and lymph node status, age did not independently predict survival outcomes in the TNBC cohort.
• Survival curves showed no significant divergence between younger and older TNBC patients, suggesting similar long-term survival trajectories.
• The lack of significant age effect persisted across multiple statistical models, including multivariate Cox regression.
• The findings challenge the assumption that younger age inherently worsens prognosis in TNBC, despite known biological aggressiveness in younger patients.