MJ only user diagnosed with advanced Lung Cancer

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This is very concerning as a long term weed smoker. I know there are other safer ways of consumption. But can we still argue that there has not been a single case of a marijuana smoker getting lung cancer?


PRESENTED ON: October 18-21, 2020

INTRODUCTION: Marijuana is the most commonly used illicit drug worldwide. Marijuana smoking shares almost the same carcinogens and irritants as tobacco smoking. Several case studies to date have documented premalignant changes in bronchial epithelium in marijuana smokers that lead to cancer. We present a case of a NSCLC in a patient who only smoked marijuana for 40 years.

CASE PRESENTATION: A 67-year-old male with past medical history of hypertension and hyperlipidemia presents with a month history of cough, congestion and intermittent hemoptysis. He had been smoking marijuana joints for about 40 years but denied any tobacco smoking. Physical examination revealed prolonged expiratory breath sounds. CT chest with contrast showed spiculated left perihilar mass measuring 6.9 x 4.01 x 3.8 cm extending into the left upper lobe (LUL) causing mild narrowing. PET/CT scan showed hypermetabolic 6 cm LUL lung mass with SUV of 22. EBUS with a transbronchial biopsy of the LUL of the lung was positive for poorly differentiated adenocarcinoma. Lymph node and adrenal gland biopsies were negative for malignancy. Ultimate staging was cT3N0M0. Genomic testing showed no expression of PDL 1 and was negative for ROS 1 rearrangement. Patient was started on neoadjuvant chemotherapy with Alimta and Carboplatin for locally advanced disease.

DISCUSSION: Around 3.9% of the global population age 15 to 64 years smokes marijuana. Marijuana smoke contains about 50% more benzopyrene and nearly 75% more benzanthracene than tobacco smoke, in addition to other carcinogens and co-carcinogens including phenols, vinyl chlorides, nitrosamines, and reactive oxygen species. Moreover, differences in the technique of smoking marijuana including deeper inhalation, lack of filter, much longer breath holding time and lower rod filtration result in a fourfold increase in deposition of the tar in the lung. Few experimental studies also suggested tetrahydrocannabinol (THC) promotes tumor growth by inhibiting antitumor immunity by a cannabinoid 2 receptor mediated pathway. In a chronic cannabis smoker, sputum cytomorphological analysis showed metaplastic cells, macrophages, pigmented macrophages and columnar cells. Endobronchial biopsies from habitual marijuana-only smokers reveal squamous cell metaplasia and cellular atypia which are precursors for malignancies. Immunohistology of bronchial tissue was also remarkable for overexpression of the nuclear proliferation antigen Ki-67, and of epidermal growth factor receptors.

CONCLUSIONS: A definite association between lung cancer and smoking marijuana has been still limited by selection bias, small sample size and failure to adjust for tobacco smoking. Given the increased popularity of marijuana use in young adults and also for medicinal purposes, more prospective studies need to be performed to establish the association of marijuana with serious adverse events including lung Ca.


People get lung cancer when they never smoked anything ever and we're never around smokers. Maybe the guy lived near an airport, maybe he was a mechanic or worked with asbestos. Sounds like reefer madness propaganda to me...
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