ABSTRACT
Background: Many human papillomavirus (HPV) types are associated with cervical cancer (CC). Therefore, HPV genotyping has both clinical and epidemiological importance. HPV 16 and 18 are two principal high-risk types responsible for more than 70% of all CC cases. Although several commercial and non-commercial genotyping assays are available, there is a need for a cost-effective and sensitive genotyping method for low- and middle-income countries. Methods: The study was aimed at evaluation of loop-mediated isothermal amplification (LAMP) assay for HPV genotyping in cervical samples. A total of six primer sets for each HPV type were selected for the assay. The LAMP assay was standardised and validated with HPV control panel. Cervical biopsies were subjected to nested multiplex polymerase chain reaction (NM-PCR; as a part of routine diagnostic workup) and LAMP (HPV 16 and 18) simultaneously. Results: A total of 225 clinical samples were processed during the study period. The sensitivity of the assay was determined using the 10-fold dilutions of positive controls. Both the HPV 16-LAMP and HPV 18-LAMP assays were shown to detect as low as 10 viral copies per reaction, which is similar to that of NM-PCR. The LAMP assay had a good agreement (new cases; 92%, post-chemoradiotherapy [post-CRT]; 89.1%) with NM-PCR for the detection of both HPV 16 and 18. As compared to histology (new cases; 79.8%, post-CRT; 51.3%), LAMP had better agreement with NM-PCR for detection of HPV from post-CRT cases. Conclusions: We evaluated the LAMP assay for simultaneous detection and typing of HPV 16 and 18. The assay had good agreement with NM-PCR for detection of both HPV 16 and 18. The LAMP assay is a promising tool for HPV genotyping along with routine cervical cytology, especially in resource-constrained settings.
ABSTRACT
Background & objectives: Locally advanced breast cancer (LABC) is associated with substantial risk of occult metastases. The patients with LABC have high rate of systemic relapse, suggesting inadequacy of the current conventional staging in detecting the occult metastatic spread. 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) is a new modality in the staging of breast cancer patients. Hence, this study was conducted to evaluate the role of 18F-FDG PET/CT in initial staging of LABC and to compare it with conventional methods. Methods: This prospective study included biopsy-confirmed female patients diagnosed with LABC meeting the selection criteria and attending surgical, medical and radiation oncology departments of a tertiary care centre in south India, from April 2013 to December 2014. Conventional workup included serum chemistry, mammogram, bone scan, contrast-enhanced CT (CECT) chest and upper abdomen and ultrasound abdomen and pelvis. All patients following conventional workup underwent 18F-FDG PET/CT. Results: In this study, 61 women with LABC underwent both conventional workup and 18F-FGD PET/CT. The 18F-FDG PET/CT, in comparison to conventional workup, revealed unsuspected N3 nodal disease in 11 more patients, revealed distant metastasis in seven more patients and also detected extra sites of metastasis in five patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT to detect distant metastasis were 95, 98, 95, 98 and 97 per cent, respectively, whereas the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of conventional imaging to detect distant metastasis were 65, 93, 81, 84 and 84 per cent, respectively. Interpretation & conclusions: The 18F-FDG PET/CT was found to be more accurate than conventional imaging for staging and modified stage and treatment in 30 and 38 per cent of patients, respectively. It was particularly useful in detecting occult distant metastasis and N3 nodal disease with an added advantage of examining whole body in single session. However, CECT chest was superior over 18F-FDG PET/CT for detecting pulmonary metastasis.