Research study · Annals of Surgical Oncology · 2026
Cannabis, Pain, and Complications: A Prospective Analysis of Cannabis Use, Opiate Consumption, and Postoperative Outcomes following Cancer-Related Abdominal Surgery
Verified on PubMed Oxford CEBM Level 2B: Clinical Cohort Study
A 2026 observational study in Annals of Surgical Oncology tested opioid analgesics in postoperative pain. Regular cannabis users reported higher pain levels and needed more pain medication after surgery than non-users, but they did not experience more surgical complications. This study suggests that regular cannabis use before major abdominal surgery is linked to higher pain.
In plain language
Study overview
Researchers followed adults undergoing major abdominal operations for cancer to see how regular use of cannabis affects pain levels, pain medication needs, and recovery complications. Patients were categorized based on their self-reported habits and confirmed with blood tests taken on the day of surgery.
Findings
Regular cannabis users reported higher pain levels and needed more pain medication after surgery than non-users, but they did not experience more surgical complications.
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The deeper readScientific analysis
Background. Cannabis use is increasing and is of particular interest to patients with cancer. There is no prospective data regarding its impact on perioperative outcomes. We asked how chronic usage of cannabis compounds (cannabinoids) impacted postoperative pain, opiate use, and complications after abdominal surgery for the treatment of cancer. Patients and Methods. This was a single center prospective observational cohort study conducted from 9/2021-3/2024 of patients 21+ years old, undergoing abdominal surgery for the treatment of cancer, and either chronic cannabinoid users (>=1x/week for last 3 months) or non-users (for the last year). Plasma cannabinoids were measured preoperatively on the day of surgery. Results. Of 223 patients screened, 64 subjects completed enrollment (24 chronic cannabinoid users, 40 non-users). Most were male (67%) and underwent an open abdominal surgery (75%). 41% developed complications, 23% of which were severe (grade 3+) complications. Chronic users with detectable cannabinoid levels had significantly higher pain scores, which persisted in multivariable analysis. Chronic users also received significantly more morphine milligram equivalents (MME) (8-hours postoperatively: 28.8 vs 9.8, p=0.036, during the total hospitalization: 273 vs 202.1, p=0.046, prescribed: 150 vs 100, p=0.047, taken through POD30: 67.5 vs 5, p=0.03). Differences in MME prescribed and taken postoperatively persisted in multivariable analysis. Chronic users had fewer overall complications (5/23 (22%) vs 21/41 (51%), p=0.025), but similar frequency to non-users for severe complications (2/23 (8.7%) vs 4/41 (9.8%), p=0.33). Conclusions. Chronic cannabinoid use increased postoperative pain and MME use for patients undergoing abdominal surgery for the treatment of cancer, but did not increase complications. Further study regarding preoperative cannabinoid cessation and use of cannabinoids for postoperative pain is warranted.
The paper
Citation
Yee EJ, Kirsch MJ, Miller OS, Sempio C, Bainbridge J, Klawitter J, et al. Cannabis, Pain, and Complications: A Prospective Analysis of Cannabis Use, Opiate Consumption, and Postoperative Outcomes following Cancer-Related Abdominal Surgery. Annals of Surgical Oncology (2026). PubMed 41131391 · DOI
Limitations the authors noted
The chronic cannabinoid group failed to recruit the goal of 40 subjects within the 24-month enrollment period. Single-center study design from an early adopter state of cannabis legalization may limit generalizability. Patients included a broad range of diagnoses and surgical procedures, making complication results hypothesis-generating. Opiate prescribing practices of individual providers were not controlled or blinded.
In practice
Why this matters
This study suggests that regular cannabis use before major abdominal surgery is linked to higher pain scores and greater narcotic medication requirements during recovery. It highlights the need to consider a patient's cannabis history in surgical planning and pain management strategies, though more research is needed to determine the exact timeline and impact of preoperative cessation.
Frequently asked questions
Clinical Questions & Answers
What were the primary clinical findings regarding Cannabinoids and Abdominal neoplasms?
Regular cannabis users reported higher pain levels and needed more pain medication after surgery than non-users, but they did not experience more surgical complications.
What study limitations or clinical safeguards should patients keep in mind?
The chronic cannabinoid group failed to recruit the goal of 40 subjects within the 24-month enrollment period. Single-center study design from an early adopter state of cannabis legalization may limit generalizability. Patients included a broad range of diagnoses and surgical procedures, m...
Browse related research
Condition: Abdominal neoplasms Condition: Postoperative complications Condition: Postoperative pain Topic: Cannabinoids Topic: Opioid
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Reviewed by Dr. Caplan on October 29, 2026.
This page is general education about a published study. It is not medical advice and does not create a doctor-patient relationship. For care specific to you, book a consultation.