Evaluation and Staging of Squamous Cell Carcinoma of the Oral Cavity and Oropharynx

68Ga-FAPI PET/CT: Tracer Uptake in 28 Different Kinds of Cancer

The recent development of quinoline-based PET tracers that act as fibroblast-activation-protein inhibitors (FAPIs) demonstrated promising preclinical and clinical results. FAP is overexpressed by cancer-associated fibroblasts of several tumor entities. Here, we quantify the tumor uptake on ⁶⁸Ga-FAPI PET/CT of various primary and metastatic tumors to identify the most promising indications for future application. Methods: ⁶⁸Ga-FAPI PET/CT scans were requested by various referring physicians according to individual clinical indications that were considered insufficiently covered by ¹⁸F-FDG PET/CT or other imaging modalities. All PET/CT was performed 1 h after injection of 122-312 MBq of ⁶⁸Ga-FAPI-04. We retrospectively identified 80 patients with histopathologically proven primary tumors or metastases or radiologically unequivocal metastatic lesions of histologically proven primary tumors. Tumor uptake was quantified by SUV_max and SUV_mean (60% isocontour). Results: Eighty patients with 28 different tumor entities (54 primary tumors and 229 metastases) were evaluated. The highest average SUV_max (>12) was found in sarcoma, esophageal, breast, cholangiocarcinoma, and lung cancer. The lowest ⁶⁸Ga-FAPI uptake (average SUV_max < 6) was observed in pheochromocytoma, renal cell, differentiated thyroid, adenoid cystic, and gastric cancer. The average SUV_max of hepatocellular, colorectal, head-neck, ovarian, pancreatic, and prostate cancer was intermediate (SUV 6-12). SUV varied across and within all tumor entities. Because of low background in muscle and blood pool (SUV_max < 2), the tumor-to-background contrast ratios were more than 3-fold in the intermediate and more than 6-fold in the high-intensity uptake group. Conclusion: Several highly prevalent cancers presented with remarkably high uptake and image contrast on ⁶⁸Ga-FAPI PET/CT. The high and rather selective tumor uptake may open up new applications for noninvasive tumor characterization, staging examinations, or radioligand therapy.

Pretreatment tumor volume and tumor sphericity as prognostic factors in patients with oral cavity squamous cell carcinoma

PURPOSE

This study was designed as a retrospective observational study, focusing on the correlation between the preoperative CT-scan tumor volume, tumor sphericity, and the disease-related prognosis.

METHODS

A total of 30 consecutive patients, affected by primary oral cancer, were retrospectively identified from our oral cancer database. The preoperative images (DICOM data) for the study population were uploaded into a modular software package designed to convert patients' medical images into 3D digital models. Multislice interpolation and threshold segmentation tools were used to segment the tumor mass. This was then converted into a 3D mesh and exported in STL format, in order to calculate the corresponding volume. We applied the concept of sphericity - a measurement of how closely the shape of an object approaches that of a mathematically perfect sphere - to the segmented tumor mass.

RESULTS

Mean tumor volume was larger in patients with tumor recurrence and/or who had died than in patients who were disease free/alive. Tumor sphericity was influential on clinical outcomes. It appeared to be lower in patients who had tumor recurrence and/or who had died (0.54 ± 0.09 and 0.53 ± 0.05) than in patients who were disease free/alive (0.65 ± 0.07). This difference was statistically significant (p < 0.05). Cumulative recurrence-free survival was 86.2% for patients with a tumor volume lower than the cut-off value. Otherwise, it was 0% for those with a tumor volume higher than the cut-off value (p < 0.01; log rank test). Cumulative recurrence-free survival was 86.3% for patients with a higher sphericity index, compared with 13.6% for those with a lower sphericity index.

CONCLUSION

The prognostic model, based on a tridimensional, CT-based characterization of the tumor size, which includes both tumor volume and tumor sphericity, uses readily available information and could be considered when formulating prognoses for patients with oral cancer.

Update 2018: 18F-FDG PET/CT and PET/MRI in Head and Neck Cancer

There are recent advances, namely, a standardized method for reporting therapy response (Hopkins criteria), a multicenter prospective cohort study with excellent negative predictive value of F-FDG PET/CT for N0 clinical neck, a phase III multicenter randomized controlled study establishing the value of a negative posttherapy F-FDG PET/CT for patient management, a phase II randomized controlled study demonstrating radiation dose reduction strategies for human papilloma virus-related disease, and Food and Drug Administration approval of nivolumab for treatment of recurrent head and neck squamous cell carcinoma.

Tumor thickness and risk of lymph node metastasis in patients with squamous cell carcinoma of the tongue

OBJECTIVES

Oral squamous cell carcinomas, and tongue malignancies in particular, are among the most common tumors of the oral cavity. Classification for therapeutic and prognostic purposes is routinely made using the tumor, node, metastasis (TNM) system; however, current definitions do not include tumor thickness. We therefore aimed to identify variables associated with survival, and to evaluate the correlation between tumor thickness and the occurrence of lymph node metastasis.

PATIENTS AND METHODS

All patients undergoing radical tumor resection for squamous cell carcinomas of the tongue between 2000 and 2012 were included. Specimens were analyzed histopathologically and co-variables were interpreted. Follow-up was performed clinically and radiologically for at least 3years according to current guidelines.

RESULTS

We included 492 patients who had a median follow-up of 70months. Variables associated with survival (p<0.05) were age, tumor stage, N stage, UICC (Union for International Cancer Control) stage, tumor grade, and recurrence. In the receiver operating characteristic curve and Youden-Index analyses, the optimal tumor thickness cut-off was 8mm to detect significant differences in overall survival.

CONCLUSION

We highlight the importance of tumor thickness as a predictive variable in tongue cancer. Specifically, a cut-off point of 8mm allowed for a more accurate and statistically precise prediction of lymph node metastasis. These findings could supplement the current classification of tongue cancers and form the basis for treatment.

Refining American Joint Committee on Cancer/Union for International Cancer Control TNM stage and prognostic groups for human papillomavirus-related oropharyngeal carcinomas

PURPOSE

To refine stage and prognostic group for human papillomavirus (HPV) -related nonmetastatic (M0) oropharyngeal cancer (OPC).

METHODS

All patients with nonmetastatic (M0) p16-confirmed OPC treated with radiotherapy with or without chemotherapy from 2000 to 2010 were included. Overall survival (OS) was compared among TNM stages for patients with HPV-related and HPV-unrelated OPC separately. For HPV-related OPC, recursive partitioning analysis (RPA) derived new RPA stages objectively. Cox regression was used to calculate adjusted hazard ratios (AHRs) to derive AHR stages. The performance of survival prediction of RPA stage and AHR stage was assessed against the current seventh edition TNM stages. Prognostic groups were derived by RPA, combining RPA stage and nonanatomic factors.

RESULTS

The cohort comprised 573 patients with HPV-related OPC and 237 patients with HPV-unrelated OPC, with a median follow-up of 5.1 years. Lower 5-year OS with higher TNM stage was evident for patients with HPV-unrelated OPC (stage I, II, III, and IV 5-year OS: 70%, 58%, 50%, and 30%, respectively; P = .004) but not for patients with HPV-related OPC (stage I, II, III, and IV 5-year OS: 88%, 78%, 71%, and 74%, respectively; P = .56). RPA divided HPV-related OPC into RPA-I (T1-3N0-2b), RPA-II (T1-3N2c), and RPA-III (T4 or N3; 5-year OS: 82%, 76%, and 54%, respectively; P < .001). AHR also yielded a valid classification, but RPA stage demonstrated better survival prediction. A further RPA (including RPA stage, age, and smoking pack-years [PYs]) derived the following four valid prognostic groups for survival: group I (T1-3N0-N2c_≤ 20 PY), group II (T1-3N0-N2c_> 20 PY), group III (T4 or N3_age ≤ 70), and group IVA (T4 or N3_age > 70; 5-year OS: 89%, 64%, 57%, and 40%, respectively; P < .001).

CONCLUSION

An RPA-based TNM stage grouping (stage I/II/III: T1-3N0-N2b/T1-3N2c/T4 or N3, with M1 as stage IV) is proposed for HPV-related OPC as a result of significantly improved survival prediction compared with the seventh edition TNM, and prognostication is further improved by an RPA-based prognostic grouping within the American Joint Committee on Cancer/Union for International Cancer Control TNM framework for HPV-related OPC.

Influence of tumor volume on survival in patients with oral squamous cell carcinoma

PURPOSE

The TNM classification is used to assess cancers of the oral cavity, and advancements in imaging techniques have revealed clear variations in tumor volume at presentation. This study therefore aimed to clarify whether preoperative imaging, with exact measurements of the tumor, could affect post-surgery survival after controlling for demographic, clinical, and tumor characteristics.

METHODS

We included 437 patients with histologically confirmed, stage T1-4, N1-3, M0, invasive squamous cell carcinoma of the tongue. Participants were assessed for recurrence every 3 months for the first 2 years, every 6 months for another 2 years, and annually thereafter; routine computed tomography was performed annually. Associations were determined using the Kaplan-Meier estimator, univariate log-rank test, and Cox proportional hazards regression models.

RESULTS

The mean survival of all patients was 68.1 ± 48.2 months. The 2- and 5-year overall survival rates were 82.2 and 66.7 %, respectively. The mean primary tumor volume was 7.14 cm(3) with a range of 1.3-24.21 cm(3). The ROC curve and Youden Index analysis revealed that the optimal cutoff volume was between ≤5.9 and ≤18.3 cm(3) for three different volume groups (p < 0.0001). Large tumor volume was associated with a significantly poorer overall survival (p < 0.0001).

CONCLUSIONS

Tumor volume was significantly associated with the overall survival of patients. This has both prognostic and reconstructive implications that will affect health-related quality of life. In addition, this will inform surgical planning and the allocation of resources.