{"id":4686,"date":"2025-09-10T09:10:33","date_gmt":"2025-09-09T23:10:33","guid":{"rendered":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/medical-cannabis-may-reduce-cancer-immunotherapy-effectiveness-study-warns\/"},"modified":"2025-11-12T21:00:24","modified_gmt":"2025-11-12T10:00:24","slug":"medical-cannabis-may-reduce-cancer-immunotherapy-effectiveness-study-warns","status":"publish","type":"post","link":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/medical-cannabis-may-reduce-cancer-immunotherapy-effectiveness-study-warns\/","title":{"rendered":"Medical Cannabis May Reduce Cancer Immunotherapy Effectiveness, Study Warns"},"content":{"rendered":"<p><img fetchpriority=\"high\" decoding=\"async\" class=\" alignright size-full wp-image-4685\" src=\"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf.jpg\" alt=\"holdpotleaf\" width=\"450\" height=\"300\" style=\"margin-bottom: 30px; margin-left: 30px; float: right;\" srcset=\"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf.jpg 1795w, https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf-300x200.jpg 300w, https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf-1024x682.jpg 1024w, https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf-768x512.jpg 768w, https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-content\/uploads\/2025\/09\/holdpotleaf-1536x1023.jpg 1536w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/>Growing evidence suggests that cannabis immunotherapy risks may significantly compromise cancer treatment outcomes, according to a comprehensive new review by Australian medical cannabis advocate Dr Ben Jansen. Furthermore, his research poses a critical question that could reshape patient care protocols: \u201cAre cannabinoids with cancer immunotherapy contributing to early death?\u201d<\/p>\n<p>Subsequently, Dr Jansen\u2019s newly published study examines three key clinical trials that reveal troubling patterns in treatment effectiveness. Meanwhile, the findings challenge the widespread assumption that medical cannabis provides only benefits for cancer patients.<\/p>\n<p><strong>Personal Tragedy Drives Scientific Investigation<\/strong><\/p>\n<p>However, Dr Jansen\u2019s investigation into medical marijuana treatment dangers stems from deeply personal circumstances surrounding his mother\u2019s death from dementia. Moreover, he explained to Newsweek that discovering medicinal cannabis might have offered her relief motivated his advocacy work in the field.<\/p>\n<p>\u201cOver time, we\u2019ve come to recognise the immunomodulatory properties of cannabinoids, which raised caution in my mind about their interaction with immune-based treatments,\u201d Dr Jansen stated. Consequently, his concerns intensified when both the public and clinicians appeared unaware of potential cannabis immunotherapy risks.<\/p>\n<p>Additionally, the issue \u201ccrystallised\u201d during a public lecture when a patient questioned why her immunotherapy wasn\u2019t working, only to reveal she had been taking high doses of medicinal cannabis.<\/p>\n<p><strong>Alarming Treatment Response Rates<\/strong><\/p>\n<p>Nevertheless, the first study Dr Jansen analysed compared patients receiving nivolumab immunotherapy alone with those combining the treatment with cannabis. In particular, the research examined 89 patients on nivolumab alone versus 51 patients using both treatments for advanced cancers including lung cancer, renal cell carcinoma, and melanoma.<\/p>\n<p>The results revealed stark differences in treatment effectiveness, with cannabis users showing significantly lower response rates (15.9% versus 37.5%). Thus, patients using cannabis were approximately three times more likely to experience poor responses to immunotherapy, highlighting serious medical marijuana treatment dangers.<\/p>\n<p>Importantly, whilst cannabis use didn\u2019t significantly impact overall survival rates, the reduced treatment efficacy raises substantial concerns about therapeutic outcomes.<\/p>\n<p><strong>Shortened Survival Times Documented<\/strong><\/p>\n<p>Similarly, the second study examined 34 patients prescribed both immunotherapy and cannabis compared with 68 patients receiving cancer treatment alone. Furthermore, the findings revealed that tumours progressed much faster in cannabis users, typically within three-and-a-half months compared to over a year for patients on immunotherapy alone.<\/p>\n<p>Moreover, the median overall survival time for cannabis users was dramatically shorter at 6.4 months compared to 28.5 months for non-users. Therefore, these statistics underscore the potential severity of cannabis immunotherapy risks for patient outcomes.<\/p>\n<p><strong>Comprehensive Analysis Confirms Concerns<\/strong><\/p>\n<p>Meanwhile, the third study investigated 105 patients with solid organ tumours receiving immune checkpoint inhibitors, with cannabis use primarily through prescribed dronabinol. Additionally, this research confirmed previous findings about medical marijuana treatment dangers.<\/p>\n<p>Cannabis use was associated with significantly worse outcomes across multiple measures: shorter median overall survival (6.7 versus 17.3 months), reduced progression-free survival (4.8 versus 9.7 months), and markedly lower disease control rates (10.7% versus 37.7%).<\/p>\n<p>Notably, these negative outcomes were most evident in white patients, suggesting potential ethnic variations in cannabinoid metabolism or immune response.<\/p>\n<p><strong>Complex Therapeutic Interactions<\/strong><\/p>\n<p>However, Dr Jansen acknowledges the inherent complexity of cannabis as a therapeutic agent when considering cannabis immunotherapy risks. Indeed, previous research has demonstrated that cannabis can suppress immune system function through active compounds including CBD, THC, and other cannabinoids.<\/p>\n<p>Conversely, laboratory and living organism studies have suggested that cannabinoids can kill cancer cells and prevent spreading. Therefore, this paradox creates significant challenges for healthcare providers weighing treatment options whilst considering medical marijuana treatment dangers.<\/p>\n<p><strong>Clinical Recommendations and Future Research<\/strong><\/p>\n<p>Consequently, Dr Jansen emphasises the critical importance of informed patient consent regarding potential interactions. In addition, he advocates for more thorough research controlling variables such as cancer type, cannabis dosage, socio-economic status, and lifestyle factors.<\/p>\n<p>When asked whether he would prescribe medical cannabis during immunotherapy, Dr Jansen responded definitively: \u201cAbsolutely\u201d not, citing current evidence suggesting possible negative interactions.<\/p>\n<p>Finally, until large, well-controlled trials provide clarity about cannabis immunotherapy risks, medical practitioners must carefully balance symptom management benefits against potential treatment compromise, ensuring patient safety remains the primary consideration.<\/p>\n<p>Source:&nbsp;<strong><a href=\"https:\/\/wrdnews.org\/medical-cannabis-may-reduce-cancer-immunotherapy-effectiveness-study-warns\/\" target=\"_blank\" rel=\"noopener\"><em>Newsweek<\/em><\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Growing evidence suggests that cannabis immunotherapy risks may significantly compromise cancer treatment outcomes, according to a comprehensive new review by Australian medical cannabis advocate Dr Ben Jansen. Furthermore, his research poses a critical question that could reshape patient care protocols: \u201cAre cannabinoids with cancer immunotherapy contributing to early death?\u201d Subsequently, Dr Jansen\u2019s newly published study [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4685,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":"","_wp_rev_ctl_limit":""},"categories":[15],"tags":[77],"class_list":["post-4686","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cannabis-as-medicine","tag-cannabis-as-medicine"],"_links":{"self":[{"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/posts\/4686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/comments?post=4686"}],"version-history":[{"count":0,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/posts\/4686\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/media\/4685"}],"wp:attachment":[{"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/media?parent=4686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/categories?post=4686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dalgarnoinstitute.org.au\/wp_site\/wp-json\/wp\/v2\/tags?post=4686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}