Gastric cancer is a tumor of the digestive tract and may not seem to be associated with bone health. But in fact, osteoporosis is one of the common complications after gastric cancer surgery, especially in older adults. How exactly does gastric cancer affect bone health, what factors are associated with it, and how can it be prevented?
Bone problems are not uncommon in patients with gastric cancer
In general, osteoporosis occurs in 15% to 38% of patients with gastric cancer after surgery, and risk factors associated with its occurrence include anemia, thinness, advanced age, chronic disease, and chemotherapy. The probability of lumbar spine osteoporosis in patients with gastric cancer was 29.8% in men and 54.5% in women, and the probability of femoral neck osteoporosis was 11.9% in men and 26.3% in women. Similar to other osteoporotic conditions, most patients with postgastrectomy osteoporosis develop back pain and pathological fractures.
In addition, the incidence of bone metastases from gastric cancer is 0.9% to 10%, with the incidence of bone metastases occurring after gastric cancer surgery (mostly within 1 to 2 years after surgery) accounting for 0.9% to 1.8%, and the actual incidence may be slightly higher. The probability of pathological fracture after bone metastasis was 22.4% and the probability of spinal cord compression was 10.6%.
Why do patients with gastric cancer develop bone abnormalities?
Cancer factors
Malignant tumors secrete a parathyroid hormone-related protein (PrHrP) that has parathyroid (PTH)-like effects, which can significantly increase bone tissue destruction and inhibit bone formation, resulting in osteoporosis.
Digestive factors
A decrease in gastric acid secretion after partial or total gastric resection predisposes to osteoporosis due to impaired digestion and absorption of calcium and other components. Postoperative chemotherapy and other treatments for gastric cancer are also often accompanied by nausea, vomiting, and loss of appetite, resulting in reduced eating and malnutrition, which can lead to disorders of calcium and phosphorus metabolism and induce abnormal bone metabolism.
Metastatic factors
In the advanced stage of gastric cancer, some patients may develop bone metastasis, which leads to bone abnormalities through the following aspects: direct tumor erosion and destruction of bone; secretion of osteolytic cytokines such as interleukin-1, interleukin-6, tumor necrosis factor, and metastatic growth factor next to the metastatic lesion, leading to abnormal activation of osteoclasts, resulting in osteolytic lesions; release of nitric oxide synthase (NOS) inhibitory factor by gastric cancer cells, causing serum The release of nitric oxide synthase (NOS) inhibitors from gastric cancer cells causes a significant decrease in serum levels of nitric oxide (NO), and low concentrations of NO can promote osteoclastic bone resorption, leading to bone loss.
How to prevent bone abnormalities?
The prevention of bone abnormalities associated with gastric cancer is important. Osteoporosis guidelines recommend the use of dual-energy x-ray absorptiometry (DXA) for bone mineral density (BMD) to diagnose osteoporosis. Patients with gastric cancer are at increased risk of fracture if other risk factors (e.g., low body weight, physical inactivity, vitamin D deficiency) are also present. The American Gastroenterological Association recommends dual-energy X-ray absorptiometry to assess BMD levels in patients who have had a gastrectomy for more than 10 years, have a history of low-trauma fractures (e.g., vertebral fractures), are postmenopausal women or men over 50 years of age, and have hypogonadism. In addition, the following methods can also help to improve bone health.
Appropriate exercise
Moderate exercise is beneficial for muscle and bone health, and weight training can induce small increases in bone density in some bones. Improving muscle function, mobility, and balance through exercise may reduce the risk of falls, which may reduce the risk of fractures.
Appropriate calcium and vitamin D supplementation
Appropriate calcium and vitamin D supplementation is often needed after gastric cancer surgery, which can help prevent osteoporosis or increased bone loss.
Other drugs
Biphosphonates, selective estrogen receptor modulators (SERMs), calcitonin, teriparatide, and estrogens may reduce the risk of fracture in patients with osteoporosis from gastric cancer.
In general, patients with gastric cancer also need to pay attention to bone health. Although the incidence of postoperative bone metastases in gastric cancer is low compared to other metastases, the problem of osteoporosis should not be ignored. The prevention of bone problems by various means under the guidance of doctors and early detection by timely bone scans and other examinations are important measures to maintain bone health. (Contributed by Xin Wang, Department of Gastrointestinal Oncology, The First Hospital of China Medical University)