Hepatitis C viral infection is a major health problem in Egypt. The management of breast cancer patients is often complicated by the presence of associated HCV infection. This study aims at investigating the epidemiological association of the two conditions. It will also investigate the possible correlation with treatment outcome.

Breast cancer is the most common cancer in adult Egyptian females. The world's highest prevalence of hepatitis C virus is found in Egypt. Several investigators examined the epidemiological association of HCV with breast cancer. Published literature reports conflicting results regarding the HCV association with breast cancer incidence. Population-based studies from HCV-endemic area demonstrated increased breast cancer incidence in HCV-positive women younger than 50 years. On the other hand, population studies from HCV-low prevalence regions failed to detect an association of the virus with breast cancer.

HCV seropositive patients constitute a large sector of oncology patients treated in Egyptian practice. HCV infection with or without clinically-significant liver disease impose several therapeutic, social and logistic problems. Recently, investigators from Mansoura University reported their findings among breast cancerpatients. According to these data, HCV-positive breast cancer patients had several markers of disease aggression such as large tumor size, high tumor grade and nodal infiltration. Moreover, HCV-NS4 (non-structural protein-4) blood levels positively correlated with the level of the known breast cancer marker CA15-3.

In the current study, the investigators will investigate the incidence of HCV seropositivity in breast cancer patients and an age-matched control group. The study also examines the association of HCV status on the patients' baseline characteristics such as tumor stage and grade and with patients' treatment plan and treatment outcome.

Specifically, the aims of the study are the following:

1. To test if HCV seropositivity is associated with breast cancer diagnosis in Egyptian population.
2. To test if HCV-positive patients harbour more aggressive breast tumors.
3. To test if HCV-positivity affects management decision in breast cancer patients.
4. To test if HCV-positive patients suffer more frequent adverse effects to breast cancer treatment.
5. To compare disease-free survival of HCV seropositive breast cancer patients vs. seronegative patients.

Inclusion Criteria:

• Biopsy-proven invasive breast cancer.

Exclusion Criteria:

• Patients with unknown viral marker status.
• Patients who did not complete their management at OCMU.
• Patients with multiple cancer diagnoses.
• Patients with virus-unrelated hepatic pathology.

Retrospective analysis of all consecuitive patients on Oncology Center of Mansoura University (OCMU) database.

All-cause Mortality and Adverse Events were not assessed in this Retrospective, observational study.

All-cause Mortality and Adverse Events were not assessed in this retrospective, observational study

This is a retrospective study. Due to limited funding, a non-selected sample of Breast Cancer was compared to a historical control derived from the data of a previously published population study. Further studies are required.