What is the most common presenting clinical manifestation of breast cancer?

The most common presenting clinical manifestation of breast cancer is the discovery of a breast mass. This often appears as a palpable lump in the breast tissue, which can be detected either by the patient during self-examination or during clinical breast examinations by a healthcare provider. The mass can vary in size, shape, and consistency, and may be associated with other symptoms, but its presence is often the first noticeable change.

Breast masses are of particular concern because they can indicate various conditions, including non-cancerous conditions such as cysts or fibroadenomas, but the context of this question specifically relates to the likelihood of a breast mass being indicative of malignancy. Regular screening and awareness are emphasized because early detection of breast cancer significantly improves treatment outcomes.

While other manifestations like nipple discharge, nipple retraction, and breast tenderness can occur in the context of breast cancer or other breast conditions, they are less commonly the first sign that prompts individuals to seek medical advice. Thus, a breast mass stands out as the primary and most commonly reported indication of breast cancer in clinical practice.