Introduction.
Gemcitabine is a standard chemo-agent for advanced pancreatic cancer. It has major adverse reactions including nausea, flu-like syndromes, myelosuppression, edema, autonomic neuropathy and myopathy. Gemcitabine-induced myopathy is extremely rare. We report a case of severe calf pain due to gemcitabine induced myopathy.
Case presentation
A 57-year-old man was diagnosed with pancreatic cancer with liver metastasis in September, 2018. He presented with severe calf pain after three cycles of chemotherapy. The chemotherapy regimen was given three times at 1 week intervals with gemcitabine and abraxane, and then there was a 2-week rest period. He did not complain any serious side effects except for abdominal discomfort after the first cycle of chemotherapy. However, after the second cycle of chemotherapy, he visited the outpatient clinic of the oncology department with muscle pain of lower limbs. After first and second chemotherapy[D1/D8] of third cycle, the patient presented with edema on both leg. He visited the emergency room with a severe calf pain, general weakness and chest discomfort. The oncologist treated conservatively with narcotic analgesics. Finally, after completing the third cycle of the chemotherapy, the patient complained of severe calf pain, which was impossible to walk. For this reason, the patient was consulted with the Rehabilitation Department. Physical examination showed bilateral lower extremity edema, tightness of both calves and hamstring, and severe tenderness on bilateral gastrocnemius muscles. The degree of pain was too severe to be diagnose with myofascial pain syndrome. We decided to perform blood test and ultrasonography. The sonographic findings showed increased echointensity predominantly of lower extremity muscles. (Figure 1) Laboratory test results showed increased creatine kinase and myoglobin, which are 10 times more than normal range. Based on these results, we diagnosed it as gemcitabine induced myopathy. Oncologist treated conservatively for symptoms of myopathy.
After 3 cycles of chemotherapy, abdominopelvic computed tomography was performed to evaluate the effect of the treatment. Re-evaluation for disease extent showed partial response on Response Evaluation Criteria in Solid Tumor(RECIST). The patient had partial response after 3 cycles of chemotherapy and no additional chemotherapy was given.
Conclusion
Gemcitabine is a standard chemotherapeutic agent for pancreatic cancer, but it is very rare to develop muscle diseases. If you are a physician interested in muscle pain, you should be able to consider myopathy for muscle aches in patients undergoing chemotherapy and need a more aggressive workup. |
