Comparison of treatment response assessed by 18F-FDG PET/CT with the histopathological response using tumor regression grading on surgically resected specimen following neoadjuvant chemotherapy in squamous cell carcinoma of esophagus

Treatment Response to Neoadjuvant Therapy in Squamous Esophageal Cancer-Correlation Between Metabolic Response and Histopathology

PURPOSE

Esophageal cancer is among the leading causes of cancer-related mortality worldwide. Patients presenting with localized and loco-regionally advanced cancer without distant metastases have reasonable survival with multimodality management. Adequate and comprehensive staging is the backbone for proper selection of patients fit for curative treatment. Positron emission tomography (PET) in combination with contrast-enhanced computed tomography (CECT) is utilized as the standard staging modality. Multimodality treatment has been able to achieve evaluable tumor responses including pathological complete response (pCR). It is, therefore, necessary to understand whether the impact of neoadjuvant therapy can be evaluated on imaging, i.e., standardized uptake value (SUV) on PET scan done for response assessment and if this can be correlated with histopathological response and later, with survival. Squamous cell carcinoma (SCC) is more common globally and in the Indian subcontinent; hence, we chose this subgroup to evaluate our hypothesis.

METHODS

This is a single institution, retrospective study. Out of the 1967 patients who were treated between 2009 and 2019, 1369 (78.54%) patients had SCC. Out of these, 44 received NACTRT, whereas 1325 received NACT followed by curative surgery. The standardized uptake value (SUV) of 18-fluorodeoxyglucose was recorded during pre- and post-neoadjuvant treatment (NAT) using positron emission tomography (PET). The histopathology of the final resection specimen was evaluated using the Mandard tumor regression grade (TRG) criteria with response being graded from 0 to 5 as no residual tumor (NRT), scanty residual tumor (SRT), and residual tumor We attempted to find a cut-off value of the post neoadjuvant SUV of the primary tumor site which correlated with achievement of better histopathological response.

RESULTS

Out of 1325 patients of SCC esophagus who underwent surgery, 943 patients had available data of TRG, and it was categorized into the 0-2 category which had 325 patients (34.5%) and 3-5 category, 618 patients (65.5%). The SUV was taken only from the PET scans done at our institution, so as to achieve a more homogenous cohort, and this was available for 186 patients, 151 from the NACT group and 35 from the NACTRT group. The ROC method was used to find the cut-off for SUV (5.05) in the NACT cohort, which depicted significant difference in the outcome. Out of these, 93 patients who underwent NACT had SUV > 5.05 and 58 had SUV < 5.05. It was found that the subjective and objective histopathological scores correlated at a p value of < 0.0001. Specifically, the majority of cases with SRT tended to be in the 3-5 category of TRG, whereas cases with NRT are predominantly in the 0-2 category. In the ≥ 5.05 category of SUV, there were 76 cases with SRT. In the NACT cohort, the < 5.05 category of SUV, there are 26 cases with SRT and 32 cases with NRT. Among cases with SRT, 74.5% had SUV ≥ 5.05, while 25.5% had SUV < 5.05. Among cases with NRT, 34.7% had SUV ≥ 5.05, while 65.3% had SUV < 5.05 (p value 0.007). No significant association was found in the radio-pathological correlation in the NACTRT group.

CONCLUSION

Our study confirms the correlation of post neoadjuvant chemotherapy PET SUV with histopathological response, the cut-off of SUV being 5.05 in our cohort. This confirms the predictive value of FDG PET as demonstrated in other studies. Furthermore, its prognostic value with respect to survival has been verified in multiple other studies. With larger scale randomized studies, we may be able to identify the group of patients who have borderline operability anatomically as well as physiologically, where alternative treatment regimens may be indicated to improve outcomes.

Clinical Effect of Laparoscopic Radical Surgery Combined with Neoadjuvant Chemotherapy in Treating Cervical Cancer and Its Influence on Postoperative Complications and Adverse Reaction Rates

Background. Cervical cancer, the only gynecological malignancy for which a clear pathogeny has been established, has an incidence rate only second to breast cancer. Objective. In our study, we aim to investigate the clinical effect of laparoscopic radical surgery combined with neoadjuvant chemotherapy in treating cervical cancer and its influence on postoperative complications and adverse reaction rates. Methods. Cervical cancer patients admitted to our hospital from August 2018 to May 2020 were retrospectively analyzed as the research object and divided into the control group and the experimental group by the draw method, with 50 cases in each group. The laparoscopic radical surgery was performed on the control group, and the laparoscopic radical surgery combined with neoadjuvant chemotherapy was performed on the experimental group to compare their effective rates, adverse reaction rates, postoperative complication rates, expression levels of serum tumor necrosis factor-α (TNF-α) and soluble interleukin-2 receptor (SIL-2R) inside the body before surgery and at one week after surgery, quality of life (QLI) scores, and Mental Status Scale in Nonpsychiatric Settings (MSSNS) scores. Results. Compared with the control group, the experimental group obtained significantly higher effective rate and QLI scores ( $P$  < 0.05) and significantly lower adverse reaction rates, postoperative complication rates, expression levels of serum TNF-α and SIL-2R inside the body at one week after surgery, and MSSNS scores ( $P$  < 0.05), with statistical differences; before surgery, the TNF-α and SIL-2R expression levels of the two groups were not significantly different ( $P$  > 0.05), but the levels at one week after surgery were significantly lower than those before, indicating statistical significance ( $P$  < 0.05). Conclusion. The clinical effect of laparoscopic radical surgery combined with neoadjuvant chemotherapy can obviously improve the effective rate of cervical cancer patients and lower the incidence rates of postoperative complications and adverse reactions.