{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T14:19:05Z","timestamp":1787840345681,"version":"build-2784847793"},"reference-count":17,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","license":[{"start":{"date-parts":[[2025,10,1]],"date-time":"2025-10-01T00:00:00Z","timestamp":1759276800000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2025,10]]},"abstract":"Abstract<\/jats:title>\n \n Background:<\/jats:title>\n \n CDK4\/6<\/jats:italic>\n inhibitors have become the standard of care for the treatment of HR+ metastatic breast cancer (MBC) based on clinical trials. However, real-world experience and efficacy in various subgroups are still lacking. Therefore, we conducted a study to analyze the use of\n CDK4\/6<\/jats:italic>\n inhibitors in the treatment of HR-positive MBC and assess the related outcomes.\n <\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n \n A total of 120 patients who received\n CDK4\/6<\/jats:italic>\n inhibitors from 2015 to 2021 were analyzed. Detailed clinical, demographic information and tumor-related factors were obtained for each patient. Progression-free survival (PFS), toxicity profile, and tolerance to\n CDK4\/6i<\/jats:italic>\n were analyzed and correlated.\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Among the 120 patients analyzed, 100 received palbociclib, while ribociclib, and abemaciclib were given to ten patients each. The median age of the population was 57 years. With a median follow-up of 28 months, the median PFS and overall survival (OS) were 25 and 54 months, respectively. The PFS did not significantly differ among different anti-hormonal agents used in combination with\n CDK4\/6<\/jats:italic>\n inhibitors. Patients who were resistant to endocrine therapy had a shorter PFS compared to treatment-naive MBC patients (22 versus 40 months). Patients with strong hormonal receptor expression had a significantly better PFS compared to those with weak expression (25 versus 14 months). Her2Neu-negative patients responded better than those with low positive expression (\n P<\/jats:italic>\n = 0.039). Visceral metastatic disease was associated with a significantly shorter PFS (17 months) compared to skeletal metastasis (32 months). There was no statistical significance when\n CDK4\/6<\/jats:italic>\n inhibitors were used in different lines of treatment or with dose reduction.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion:<\/jats:title>\n \n CDK4\/6<\/jats:italic>\n inhibitors demonstrate similar responses and better tolerance in real-world evidence. Further studies are necessary to identify other predictive and resistance factors for the use of\n CDK4\/6<\/jats:italic>\n inhibitors.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.4103\/ijc.ijc_643_23","type":"journal-article","created":{"date-parts":[[2026,3,9]],"date-time":"2026-03-09T09:01:39Z","timestamp":1773046899000},"page":"541-547","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":1,"title":["Clinical outcomes and safety study of CDK4\/6 inhibitors in hormone-positive metastatic breast cancer - A real-world tertiary cancer center experience"],"prefix":"10.4103","volume":"62","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2110-1233","authenticated-orcid":false,"given":"K. S.","family":"Sandeep","sequence":"first","affiliation":[{"name":"Department of Medical Oncology, Rajiv Gandhi Superspeciality Hospital (OPEC), Raichur, Karnataka, India"},{"name":"Consultant Medical Oncologist, Nandadeepa Cancer Clinic, Raichur, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-4900-4936","authenticated-orcid":false,"given":"Sandhya","family":"Appachu","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, Sri Shankara Cancer Hospital and Research Centre, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-0144-5835","authenticated-orcid":false,"given":"Ravi B.","family":"Diwaker","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, Sri Shankara Cancer Hospital and Research Centre, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-0614-0027","authenticated-orcid":false,"given":"Sai","family":"Vivek","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, Sri Shankara Cancer Hospital and Research Centre, Bengaluru, Karnataka, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5632-5275","authenticated-orcid":false,"given":"Vijai V. 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