World J Oncol

World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Oncol and Elmer Press Inc

Journal website https://www.wjon.org

Review

Volume 000, Number 000, October 2021, pages 000-000

Genetic Polymorphisms in Pharmaceuticals and Chemotherapy

Table

**Table 1.** Association Between Polymorphism and Cancers
Serial no.	Cancer	Genetic polymorphisms	Importance	References
GST: glutathione S-transferase; 5-FU: 5-fluorouracil; MTHFR: methylene tetrahydrofolate reductase. TPMT: thiopurine methyltransferase; DPYD: dihydropyrimidine dehydrogenase; SNP: single nucleotide polymorphism.
1.	Colon, breast, pancreas, bowel cancer	CYP2 enzymes	CYP2A6*4 allele had decreased conversion of Tegafur into 5-FU.	[14, 15]
2.	Breast cancer, colorectal cancer and leukemia	GST enzymes	GSTA1B allele has increased survival for breast cancer.	[14]
3	Colorectal cancer	UDP- glucuronosyltransferase enzyme	UGT1A1*28 variant leads to higher levels of irinotecan in the blood leading to severe neutropenia and diarrhea.	[16, 17]
4	Lymphoblastic leukemia	TPMT enzyme	TPMT3A and TPMT3C alleles can cause hematopoietic toxicity.	[14, 16]
5	Colorectal cancer, breast cancer, head-and-neck cancer	DPYD enzyme	DPD is responsible for metabolizing 5-FU into inactive metabolites and patients with deficiency are associated with diarrhea, neurotoxicity, and myelosuppression.	[24]
6	Colorectal cancer, ovarian cancer, gastric cancer	MTHFR	MTHFR protein is important in folate metabolism and the synthesis of DNA and those with mutations are at higher risk for toxicity.	[23]
7	Bladder cancer, non-small cell lung cancer	ERCC1 enzyme	ERCC1 proteins are important for gene specific repair and high levels of the protein is associated with worse outcomes due to lesser response to platinum-based chemotherapy.	[23]
8	Ovarian cancer	ABCB1, ABCC2	SNPs in these transporters are associated with drug resistance to irinotecan.	[9, 23]