Published online Nov 24, 2020. doi: 10.5306/wjco.v11.i11.959
Peer-review started: August 5, 2020
First decision: September 17, 2020
Revised: October 1, 2020
Accepted: October 19, 2020
Article in press: October 19, 2020
Published online: November 24, 2020
Processing time: 104 Days and 20 Hours
Colorectal cancer (CRC) is the third leading cause of cancer-related death in males and females in the United States. Approximately, 20%-22% of patients have metastatic disease at the time of presentation, and 50%-60% will develop metastasis over the course of their disease. Despite advances in systemic therapies, there remains a paucity of effective third- and later-line therapies for patients with ongoing disease progression. However, rechallenging chemo-resistant CRC tumors with previously administered therapies is an emerging concept that may be a life-prolonging option for heavily treated metastatic colorectal cancer (mCRC).
A 41-year-old man with no previous medical history initially presented with worsening diffuse abdominal tenderness. Computed tomography was significant for a splenic flexure mass and hepatic lesions concerning for metastatic disease. He underwent a colectomy with anastomosis. Postoperative pathology was diagnostic for moderately to well-differentiated adenocarcinoma (T4bN1bM1a). He received adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX), but therapy was discontinued due to the development of atrial fibrillation. Additional workup indicated a carcinoembryonic antigen level of 508.2 ng/mL, and mutational analysis found that the tumor was microsatellite instability-high and KRAS/BRAF wild-type. He was started on irinotecan with oxaliplatin (IROX), and bevacizumab (14 cycles), developed disease progression, was transitioned to FOLFOX and cetuximab, and then eventually three cycles of pembrolizumab. Following disease progression, he was rechallenged with IROX therapy, as he previously responded well to oxaliplatin-based therapy. The IROX rechallenge provided this patient with a ten-month survival benefit, decreased metastatic burden, and marked improvement in his clinical condition.
Rechallenge of previous lines of well-tolerated systemic chemotherapy regimens may be a valuable therapeutic strategy in patients with heavily-treated mCRC.
Core Tip: Despite advances in therapeutic strategies, colorectal cancer (CRC) remains a deadly disease. There are limited options for patients with chemo-refractory mCRC. We present a case of a patient with heavily treated metastatic colorectal cancer (mCRC) that was responsive to oxaliplatin-based rechallenge therapy. Oxaliplatin rechallenge therapy provided this patient with a ten-month survival benefit, marked improvement in his clinical condition, performance status, and quality of life. This case highlights the importance of considering rechallenge therapy in patients with chemo-refractory mCRC. Monitoring for oxaliplatin-associated peripheral sensory neuropathy should be considered for patients who are candidates for oxaliplatin rechallenge therapy.