Concern over “hip cancer” often arises from persistent, unexplained pain in the joint area. Cancer rarely originates directly in the hip joint itself. Instead, the term commonly refers to malignancies that develop in or spread to the bones of the hip—specifically the pelvis, the acetabulum (hip socket), or the proximal femur (upper thigh bone). This article clarifies this terminology and discusses the specific types of cancer that affect this region.
Clarifying the Term “Hip Cancer”
The phrase “hip cancer” is not a formal medical diagnosis but a common, non-specific term for any malignant tumor found in the structures around the hip. It refers to cancers affecting the bony or soft tissues of the pelvic girdle and upper leg. The distinction between where a cancer started is important, as it determines the specific type of disease and treatment plan.
Malignancies in this area fall into two categories: primary and metastatic. Primary bone cancer is extremely rare and begins within the bone tissue itself. Metastatic cancer, also known as secondary cancer, is much more common and involves cancer cells that have traveled from an original tumor site elsewhere in the body to the hip bones.
Primary Bone Cancers and Metastasis in the Hip
Metastatic cancer is the most frequent reason cancer is found in the hip bones, particularly in adults. The pelvis and the proximal femur are common sites for secondary tumors due to their rich blood supply and the presence of red bone marrow. Cancer cells from distant organs enter the bloodstream and become lodged in these vascular areas, initiating tumor growth.
Primary cancers most likely to spread to the bone include malignancies of the breast, prostate, lung, kidney, and thyroid. Prostate cancer typically causes osteoblastic metastases, encouraging excessive bone formation and making the affected area denser. Conversely, breast cancer often results in osteolytic metastases, which cause bone breakdown and weakening.
Primary bone cancers, which start in the hip bones, are statistically rare, accounting for less than one percent of all cancer cases. Osteosarcoma and Ewing sarcoma are two main types that can affect the hip bones. Osteosarcoma is seen in children, adolescents, and young adults, frequently developing in the long bones near the knee or hip.
Ewing sarcoma also affects younger populations and can originate in the pelvis or thigh bone. Chondrosarcoma, another primary tumor, begins in cartilage cells and is more commonly found in adults, often affecting flat bones like the pelvis and hip. Beyond the bone, soft tissue sarcomas can arise in the muscles, fat, and fibrous tissues surrounding the hip joint.
Identifying Symptoms and the Diagnostic Process
The most common symptom of cancer affecting the hip region is persistent, localized pain. Unlike typical orthopedic pain, cancer-related bone pain often worsens over time, may not resolve with rest, and frequently intensifies at night. As the tumor grows, individuals may notice swelling, a palpable lump, or stiffness that limits the range of motion.
A significant concern is the potential for a pathological fracture, where a bone breaks under minimal or no trauma because cancer has weakened its structure. Since these symptoms can mimic common non-cancerous conditions like arthritis or bursitis, a specialized evaluation is necessary. Systemic symptoms like unexplained weight loss, fatigue, or fever can also accompany the localized discomfort.
The diagnostic process begins with a medical history and initial imaging, typically an X-ray, which can reveal characteristic bone destruction or new bone growth. If the X-ray is suspicious, more detailed imaging follows, including Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) scans. These scans better visualize the size and extent of the tumor within the soft tissues and bone. Positron Emission Tomography (PET) scans may also be used to check for cancer spread throughout the body.
The definitive diagnosis requires a biopsy, where a small sample of the suspicious tissue is removed, often using a CT-guided needle, and examined under a microscope. The biopsy confirms the malignancy and identifies the specific type of cancer, which is crucial for treatment planning. Treatment depends on whether the cancer is a primary tumor or a metastasis, and can involve a combination of surgery, radiation therapy, chemotherapy, or targeted drug therapies.