Complementary Roles of Squamous Cell Carcinoma Antigen and ¹⁸F-FDG PET/CT in Suspected Recurrence of Cervical Squamous Cell Cancer

Abstract

Purpose: To assess the clinical value of FDG PET/CT and evaluate the complementary roles of serum squamous cell carcinoma antigen (SCCAg) and FDG PET/CT in the diagnosis of suspected recurrent of cervical squamous cell cancer. Methods: Serum SCCAg levels were retrospectively reviewed in patients previously treated for cervical squamous cell carcinoma, who had suspected recurrence of cervical cancer and who had undergone FDG PET/CT scans. The clinical impact of elevated SCCAg (>1.5 ng/ml) and negative SCCAg (≤1.5 ng/ml) levels were analyzed based on the results of PET/CT and final diagnosis. Results: The overall patient-based sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of PET/CT for the detection of tumor recurrence or malignancy were 100% (86/86), 80.8% (21/26), 95.5% (107/112), 94.5% (86/91) and 100% (21/21), respectively. Of the 112 patients included in this study, recurrence or malignancy was detected by PET/CT in 62 of the 64 patients with elevated SCCAg, compared to 24 of the 48 patients with negative SCCAg levels. The overall patient-based PPV, NPV, sensitivity and accuracy of SCCAg for the detection of tumor recurrence or malignancy were 96.9% (62/64), 50% (24/48), 72.1% (62/86) and 76.8% (86/112), respectively. The five false-positive PET/CT results were all associated with patients with negative SCCAg levels. The PPV of positive PET/CT-associated elevated SCCAg for the detection of tumor recurrence or malignancy was 100% (62/62). The NPV of negative SCCAg-associated negative PET/CT was 100% (19/19). Conclusions: Serum SCCAg evaluation and FDG PET/CT imaging can be complementary techniques in cases of suspected recurrent cervical squamous cancer. Positive PET/CT with elevated SCCAg can predict recurrence. Although PET/CT cannot confidently be deferred due to a negative SCCAg test, the possibility of a false-positive PET/CT in those cases may have diagnostic importance.

Clinical Value of Combining 18F-FDG PET/CT and Routine Serum Tumor Markers in The Early Detection of Recurrence Among Follow-up Patients Treated for Cervical Squamous Cell Carcinoma

“…In a comparative study between 18 F-FDG PET and CT/MRI, it was reported that 18 F-FDG PET was superior to CT in detecting small metastatic lymph nodes, whose principle is based on increased glycolysis levels in tumor cells 31 . Our study demonstrated a good overall patient-based sensitivity, accuracy, PPV and NPV of 18 F-FDG PET/CT in detecting recurrent cervical cancer that are consistent with previous studies 16 - 18 , 22 . However, the specificity is lower (70.6%) compared to those studies.…”

“…Another reason that could explain this is the inclusion of CEA in the study that accounted for most of the false positive results. False positive results have also been reported in several previous reports and these results are explained by physiological hypermetabolism and reactive lymph nodes 8 , 17 , 18 .…”

“…Previous reports have shown the clinical value 18 FDG PET/CT in patients with elevated serum tumor markers during follow-up of cervical cancer. All these studies have evaluated the clinical significance of 18 FDG PET/CT with elevated SCC Ag or CEA in the detection of cervical cancer recurrence, but currently, there are no reports on 18 FDG PET/CT and combined elevation of SCC Ag and CEA for early recognition of recurrence in treated cervical cancer cases 15 - 18 .…”

Tumour-associated antigens and their anti-cancer applications

“…SCCA has been identified as a tumour marker in the diagnosis and treatment of cervical cancer. An increased level of SCCA was found to correlate with cervical cancer recurrence and lymph node metastasis (Hu et al 2015;Li et al 2015b). It is a typical tumour marker that is of clinical value in uterine cervical cancer.…”

“…An increased level of SCCA was found to correlate with cervical cancer recurrence and lymph node metastasis (Hu et al . ; Li et al . ).…”