RESUMEN
Oral squamous cell carcinoma is considered a rare complication of post-haematopoietic stem cell transplantation (HSCT). Early detection of these lesions is further complicated by the overlapping clinical appearance and presentation of lesions associated with chronic graft versus host disease (cGVHD). We report a case of oral squamous cell carcinoma in a 33 year-old man who presented with severe intraoral pain on the lower left side of the cheek and jaw 19 months after undergoing HSCT for the treatment of underlying acute lymphoblastic leukaemia. He was previously treated with intravenous cyclophosphamide as a conditioning regimen for HSCT and later developed cGVHD of the liver, eyes, and gut, which resolved with treatment. Intraoral examination revealed two separate lesions. The first lesion presented as a raised oval nodular swelling with a well-circumscribed margin and irregular surface on the left buccal mucosa. A similar, but more extensive, lesion was noted on the left lingual gingiva and was associated with spontaneous bleeding. Biopsy revealed that both lesions were well-differentiated squamous cell carcinomas and were p16 positive. He underwent palliative radiotherapy but succumbed to his disease 3 months after initiation of treatment.
RESUMEN
OBJECTIVE: The present study established a real-time loop-mediated isothermal amplification (qLAMP) for rapid detection of human papillomavirus subtype 16 (HPV-16) in oral squamous cell carcinoma (OSCC). METHODS: The qLAMP assay was optimized targeting the HPV-16 E7 gene. The analytical sensitivity and specificity of the assay were determined using HPV-18 (ATCC® 45152D™), HPV-35 (ATCC® 40330™), HPV-43 (ATCC® 40338™) and HPV-56 (ATCC® 40549™) viral strains and oral bacteria. HPV-16 standard curve was constructed for determination of HPV-16 viral load. The diagnostic performance of the assay was evaluated from 63 OSCC patients comprising 63 tissue, 13 saliva and 49 blood samples, in comparison with p16 immunohistochemistry (IHC), in-house PCR and nested PCR assays. RESULTS: The detection limit of developed LAMP and PCR assays was 4.68 × 101 and 4.68 × 103 copies/µl, respectively. qLAMP assay enabled detection of positive results as early as 23 min at 67 °C. This assay can detect HPV-16 positivity in 23 % (3/13) saliva and 4.8 % (3/63) tissue samples with the viral load ranging from 4.68 × 101 to 4.68 × 104 copies/µl. HPV-16 positivity was not detected in all the blood samples. The sensitivity and specificity of qLAMP were 100 % in comparison with that of p16 IHC and nested PCR. CONCLUSION: This study reports for the first time on the use of qLAMP assay for detection of HPV-16 in OSCC in both tissue and saliva as the sample matrix which holds promise in improving the diagnostic application owing to its rapidity, simplicity, high sensitivity and specificity.