Cancer affecting the shoulder can originate directly in the bones or soft tissues of the shoulder region (primary cancer) or spread from another part of the body (metastatic cancer). Primary cancers are less common than metastatic ones. This overview explores the types of cancer that can affect the shoulder, their common symptoms, diagnostic methods, and treatment options.
Types of Cancer Affecting the Shoulder
Cancer in the shoulder can be primary bone tumors, primary soft tissue sarcomas, or metastatic disease. Primary bone cancers originate in the bone itself. Common types include osteosarcoma, which often affects teenagers and young adults in the upper arm bone (humerus). Chondrosarcoma usually starts in cartilage cells, prevalent in individuals over 40, often found in the shoulder blade (scapula) or upper arm. Ewing sarcoma is common in teenagers and young adults and can affect any bone, including the shoulder blade.
Soft tissue sarcomas develop in supportive tissues like fat, muscle, nerves, and fibrous tissue, occurring anywhere in the body, including the shoulder. Examples include synovial sarcoma (around joints), liposarcoma (fat cells), leiomyosarcoma (muscle tissues), and rhabdomyosarcoma (muscle cells). Ewing sarcoma can also begin in soft tissues.
Metastatic cancer is more common in the shoulder, occurring when cancer cells from a primary tumor elsewhere travel to the shoulder, often via the bloodstream or lymphatic system. Common primary sites that metastasize to the shoulder include the lungs, breast, prostate, kidney, and thyroid. Lung cancer, especially a Pancoast tumor, can spread to the ribs, vertebrae, nerves, or blood vessels in the upper chest and shoulder, causing pain.
Common Symptoms and Warning Signs
Shoulder cancer symptoms can be mistaken for common musculoskeletal issues, making awareness of specific warning signs important. Persistent pain in the shoulder is a common symptom, especially if it worsens at night or during rest and is not relieved by typical pain relievers. This pain may start as dull and intermittent, gradually becoming constant and increasing with movement.
A palpable mass or swelling near the affected area is another frequent sign, which may or may not be painful. This lump can appear without prior injury and may grow over time. Reduced range of motion in the shoulder joint can also occur, making daily activities difficult.
Unexplained weakness in the arm or shoulder, or nerve compression symptoms like numbness or tingling, can indicate the tumor is pressing on nearby nerves or muscles. A weakened bone due to cancer may lead to a pathological fracture, where a minor injury causes a break. Systemic symptoms, such as unexplained weight loss, persistent fatigue, or fever and night sweats, may also accompany localized symptoms, particularly with metastatic disease.
Diagnostic Methods
Diagnosing cancer in the shoulder begins with a physical examination and a review of the patient’s medical history. The doctor assesses the shoulder for masses, swelling, tenderness, and movement limitations. Imaging techniques then play a significant role in identifying and characterizing potential tumors.
X-rays are often the initial imaging test, revealing bone abnormalities. Computed Tomography (CT) scans provide detailed cross-sectional images, helping determine the precise location, shape, and size of tumors in both bone and surrounding soft tissues. Magnetic Resonance Imaging (MRI) is valuable for evaluating tumor extent within bone and soft tissues, offering clear visualization of its relationship to nerves and blood vessels. Positron Emission Tomography (PET) scans, often combined with CT (PET/CT), detect metabolically active cancer cells throughout the body, assisting in identifying primary tumors and metastatic spread. A bone scan also helps identify malignant bone lesions.
A definitive diagnosis requires a biopsy, taking a tissue sample from the suspicious area for pathological examination. This can be a needle biopsy or an open surgical biopsy. A pathologist then analyzes the sample to confirm cancer and determine its type and grade. Blood tests may also support the diagnostic process, though they are not definitive for diagnosing shoulder cancer alone.
Treatment Options
Treating shoulder cancer involves a multidisciplinary approach, with the plan tailored to the cancer’s type, stage, location, and the patient’s overall health. Surgery is a common treatment, aiming to remove the tumor along with a margin of healthy tissue. For shoulder cancers, limb-sparing surgeries are often preferred to preserve arm function, though amputation might be considered if the tumor is large or involves critical structures.
Radiation therapy uses high-energy rays to destroy cancer cells. It can be used before surgery to shrink the tumor, after surgery to eliminate remaining cells, or for palliative pain management. This therapy can be delivered externally or internally (brachytherapy).
Chemotherapy uses powerful drugs to kill cancer cells throughout the body, often administered intravenously. It is frequently used for systemic cancers, as adjuvant therapy after surgery to reduce recurrence risk, or as neoadjuvant therapy before surgery to shrink tumors.
Newer treatment approaches include targeted therapy and immunotherapy. Targeted therapies focus on specific molecules involved in cancer cell growth and survival, while immunotherapies boost the body’s own immune system to fight cancer cells. These treatments are options for certain advanced soft tissue sarcomas.