Tumor lymphocyte infiltrations decrease the risk of late relapse in breast cancer patients

Background

Tumor lymphocyte infiltrations (TLI) seem to be a prognostic factor for survival in hormone receptor negative breast cancer (i.e. triple negative and HER2 positive). The majority of breast cancer patients relapse early in the first five years after diagnosis. The impact of TLI on late relapses in breast cancer patients is unknown.

Methods

Data of patients with early breast cancer treated in years 1984-1988 at the Institute of Oncology Ljubljana, Slovenia, were analysed retrospectively from patient's charts. We evaluated the prognostic value of TLI on late relapses (>5 years after diagnosis).

Results

In 1034 patients (median age 57 years, 61% postmenopausal) primary treatment was surgical by modified radical mastectomy (87%) or breast conserving surgery (13%). All had axillary dissection and 12% adjuvant radiation. 47% were node negative, 51% size of tumor 2-5 cm, 40% grade II and 21% grade III, 15% had lymphovascular invasion (LVI) and 42% TLI, 50% positive estrogen receptors (ER), 30% positive progesterone receptors (PR). HER2 status was unknown. 30% of patients received adjuvant chemotherapy (CMF schedule), 16% adjuvant hormonal therapy with tamoxifen, and 3% both chemo- and hormonal therapy. 516 (50%) of patient relapsed during the whole follow-up time (median follow-up time was 26.5 years). At 5 years 595 patients were alive and relapse-free, 150 (14.5%) patients relapsed after 5 years after diagnosis. In univariate analysis TLI (HR 0.56; 95% CI 0.40-0.78), nodal stage (HR 1.39; 95% CI 1.14-1.69) and PR (HR 1.78; 95% CI 1.25-2.54) were found as prognostic factors for relapse. ER (HR 1.39; 95% CI 0.99-1.95) and LVI (HR 1.63; 95% CI 0.97-2.73) were nearly statistically significant. In multivariate Cox analysis a favourable prognostic factor for relapse was TLI (HR 0.58; 95% CI 0.40-0.84; p = 0.004) and two unfavourable prognostic factors were positive PR (HR 1.65; 95% CI 1.14-2.39; p = 0.007) and nodal stage (HR 1.43; 95% CI 1.13-1.80; p = 0.03).

Conclusions

Our data indicate that TLI could decrease the risk of late relapse in breast cancer patients indicating the significance of immune response mechanisms as a potential therapeutic target in breast cancer. Prospective studies to test this hypothesis are needed.

Clinical trial identification

National Medical Ethics Comittee at Ministry of Health, Republic of Slovenia, Number 121/07/02

Legal entity responsible for the study

Institutional ethics commitee, Institutional review board

Funding

None

Disclosure

All authors have declared no conflicts of interest.