Severe Gastrointestinal Mucositis Following Concurrent Palbociclib and Palliative Radiation Therapy

Abstract

Background/Aim: Palbociclib is an FDAapproved cyclin-dependent kinase inhibitor for the treatment of advanced breast cancer. Limited information is available regarding the toxicity of palbociclib and concurrent radiation therapy. Case Report: Herein, we report a case of esophageal toxicity in a patient treated with palbociclib and radiation therapy. A 63-year-old woman was treated with palbociclib followed by palliative radiation therapy. The patient presented three days after completing radiation therapy with severe odynophagia, and dysphagia and was found to have grade 2-3 esophageal ulcers. Palbociclib and radiation therapy was held on admission, and a resolution of her symptoms and improvement in her oral intake was noted at which time she was restarted on palbociclib with no further radiation treatment. Conclusion: Caution is advised when patients are undergoing concurrent palbociclib and even low-dose palliative radiation treatment. In these patients, providers should maintain a high index of suspicion for toxicities such as dermatitis or mucositis.

Unexpected toxicity of CDK4/6 inhibitor palbociclib and radiotherapy

“…22,23 Furthermore, hypofractionated radiotherapy is often applied showing several cases of G3 skin and gastrointestinal toxicity. [13][14][15][16][17][18] However, the nature and limited size of these studies, including our study, make it difficult to reliably predict the absolute risk of increased toxicity.…”

“… 15 , 16 Grade 3 esophagitis is described in two case reports (30 × 2 Gy and 5 × 4 Gy), combined with G3 dermatitis in one patient. 17 , 18 Also, a conference abstract reports unexpected pronounced pulmonary fibrosis and radiation pneumonitis. 19 …”

“…15,16 Grade 3 esophagitis is described in two case reports (30 Â 2 Gy and 5 Â 4 Gy), combined with G3 dermatitis in one patient. 17,18 Also, a conference abstract reports unexpected pronounced pulmonary fibrosis and radiation pneumonitis. 19 We present three patients with unexpected toxicity after radiotherapy in combination with palbociclib (Table 1), which indicates a possible severe interaction between these treatments.…”

Safety of CDK4/6 Inhibitors Combined with Radiotherapy in Patients with Metastatic Breast Cancer: A Review of the Literature

“…Based on the analysis of the 19 selected articles, 373 patients who received radiotherapy combined with CDK4/6 inhibitors were evaluated across 9 retrospective studies [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], 4 case reports [ 22 , 23 , 24 , 25 ], 3 case series [ 26 , 27 , 28 ], and 3 letters to the editor [ 29 , 30 , 31 ], as shown in Table 1 .…”

“…Palbociclib was notably the most prescribed drug, followed by ribociclib and abemaciclib. There were 10 publications [ 17 , 18 , 19 , 22 , 24 , 25 , 26 , 28 , 29 , 30 ] describing patients who received exclusively palbociclib and 7 publications [ 13 , 14 , 15 , 16 , 20 , 21 , 31 ] that included the three drugs, but of these; palbociclib was also the most prevalent administered drug. In exceptions to this, Meattini [ 27 ] and Erjan [ 23 ] presented data on patients who received only ribociclib, with the first describing five cases and the second reporting a case.…”