[A Case of Triple Negative Breast Cancer with Successful Control of Recurrent Disease Activity for More than Ten Years].

A woman in her 70s underwent mastectomy plus axillary lymph node excision(Bt plus Ax)in December 2011 for left breast cancer classified as pT2N1M0, pStage ⅡB. The tumor was identified as an invasive ductal carcinoma(IDC), neural/ glial antigen 2(NG2), pT2(35 mm), INF γ, ly2, v0, g+, f+, s+, extensive intraductal component(EIC)-negative, ICT- positive, NCAT-positive, n(4/18), estrogen receptor(ER)-negative, progesterone receptor(PgR)-negative, human epidermal growth factor receptor 2(HER2)-negative, Ki-67 30-40%. Postoperative adjuvant fluorouracil plus epirubicin HCl plus cyclophosphamide(FEC)plus paclitaxel(PTX)therapy was administered. The patient refused to undergo postoperative radiation therapy. Two years after the surgery, she was diagnosed as having a lung metastasis and local disease recurrence. Biopsy of the local recurrent lesion revealed the same histopathological diagnosis as before. Capecitabine was selected for treatment of the recurrent lesion. After 2 years of capecitabine treatment, the response was rated as progressive disease (PD). At this time, eribulin mesylate was selected, along with intensity-modulated radiation therapy(IMRT). This resulted in disappearance of the tumor on imaging. However, considering that the histological findings did not suggest complete response(CR)and that the tumor was triple-negative(TN), we adopted a strategy of continuing the drug therapy at reduced dose level. With this strategy, the disease activity could be successfully controlled for 6.5 years. Subsequently, liver metastasis was detected, and the drug was switched to vinorelbine ditartrate(a drug with less non-hematological toxicity). Meanwhile, a breast cancer susceptibility gene(BRCA)analysis was performed in January 2021, which was negative. Subsequently, in September 2021, we obtained a positive result for PDL1-SP142 and negative result for 22C3. About half a year later, ie, in October 2021(11 years after the surgery), we detected an increase in the size of the liver metastasis and selected atezolizumab and nab-PTX for treatment. Applicable regimens of drug therapy are still available at present and drug therapy has been continued based on a discussion and mutual understanding of the adverse reactions, etc. with the patient. Few reports have been published concerning long-term survivors among TN breast cancer cases.