Triple Viral Infections in Advanced Breast Cancer: Insights from a Three-Case Report and Literature Review

<b>Background and clinical significance:</b> Viral infections are typically considered contributing or secondary factors in the development of breast cancer. <b>Case presentation</b>: This case report presents three instances of advanced breast cancer associated with triple viral infections. Case 1 involves a 78-year-old woman diagnosed with grade 2 invasive ductal carcinoma positive for HPV-18, CMV, and BLV. Case 2 describes a 39-year-old woman with grade 2 invasive ductal carcinoma, positive for HPV-16, CMV, and BLV. Case 3 is a 52-year-old woman with grade 3 invasive ductal carcinoma, positive for HPV-16, BLV, and MMTV. These cases suggest a possible correlation between viral co-infections and breast cancer aggressiveness, posing new questions about the role of viral infections in cancer development and prognosis. <b>Conclusions:</b> The findings contribute to growing evidence that viral infections may influence the progression and therapeutic response of breast cancer, warranting further investigation into targeted preventive measures including vaccinations.