A PET/CT volumetric parameter predicts prognosis of non-small cell lung cancer treated using preoperative chemoradiotherapy and surgery: A retrospective case series study

Prognostic Value of FDG PET Metabolic Parameters Before and After 42 Gy of Radiochemotherapy in Patients with Inoperable Stage III Nonsmall Cell Lung Cancer

The purpose of this study was to assess the prognostic value of 18F-FDG PET parameter variation between baseline and 42 Gy (PET2) of radiochemotherapy at 6 mo and 1 y of evaluation in patients with stage III inoperable nonsmall cell lung cancer based on RECIST 1.1. Methods: In total, 158 patients in a prospective multicenter phase II/III study were analyzed. Patients were randomized into 2 groups: an experimental arm (group A) and a standard arm (group B). Patients from group A with residual metabolism on PET2 (group A+) at 42 Gy received a radiation boost (74 Gy). Patients without residual uptake on 18F-FDG PET at 42 Gy (group A-) and patients in group B received a standard radiotherapy dose (66 Gy). We compared group A with group B. The 18F-FDG PET parameters SUVmax, SUVmean, SUVpeak, peak SUV normalized on lean body mass, mean SUV normalized on lean body mass, total lesion glycolysis, total metabolic tumor volume (MTV) (tumor and nodes), and tumor MTV were measured. All patients were evaluated with RECIST 1.1 using CT at 6 mo and 1 y after radiochemotherapy. Progression-free survival and overall survival were evaluated. Results: Except for the radiotherapy dose (P < 0.001), patient demographic characteristics were similar between the 2 groups (A vs. B). All 18F-FDG PET uptake and volume parameter measurements were correlated. Therefore, only the change in SUVmax (ΔSUVmax) and total MTV were selected for the analysis. There was no significant difference in any variable between the 2 groups. In the multivariate analysis, ΔSUVmax appeared to be the most important prognostic factor for overall survival, and SUVmax of PET2 appeared to be the most important prognostic factor for progression-free survival. Conclusion: 18F-FDG PET at 42 Gy can be used to identify good responders to radiochemotherapy in patients with inoperable stage III nonsmall cell lung cancer. The SUVmax of PET2 and ΔSUVmax are independent prognostic factors.

Multimodal analysis suggests differential immuno-metabolic crosstalk in lung squamous cell carcinoma and adenocarcinoma

Immunometabolism within the tumor microenvironment is an appealing target for precision therapy approaches in lung cancer. Interestingly, obesity confers an improved response to immune checkpoint inhibition in non-small cell lung cancer (NSCLC), suggesting intriguing relationships between systemic metabolism and the immunometabolic environment in lung tumors. We hypothesized that visceral fat and ¹⁸F-Fluorodeoxyglucose uptake influenced the tumor immunometabolic environment and that these bidirectional relationships differ in NSCLC subtypes, lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). By integrating ¹⁸F-FDG PET/CT imaging, bulk and single-cell RNA-sequencing, and histology, we observed that LUSC had a greater dependence on glucose than LUAD. In LUAD tumors with high glucose uptake, glutaminase was downregulated, suggesting a tradeoff between glucose and glutamine metabolism, while in LUSC tumors with high glucose uptake, genes related to fatty acid and amino acid metabolism were also increased. We found that tumor-infiltrating T cells had the highest expression of glutaminase, ribosomal protein 37, and cystathionine gamma-lyase in NSCLC, highlighting the metabolic flexibility of this cell type. Further, we demonstrate that visceral adiposity, but not body mass index (BMI), was positively associated with tumor glucose uptake in LUAD and that patients with high BMI had favorable prognostic transcriptional profiles, while tumors of patients with high visceral fat had poor prognostic gene expression. We posit that metabolic adjunct therapy may be more successful in LUSC rather than LUAD due to LUAD's metabolic flexibility and that visceral adiposity, not BMI alone, should be considered when developing precision medicine approaches for the treatment of NSCLC.

Tolerability and safety of adjuvant chemoradiotherapy with S-1 after limited surgery for T1 or T2 lower rectal cancer

BACKGROUND

Chemo-radiotherapy (CRT) after local excision for pT1 with high-risk features or pT2 rectal cancer is recommended as an optional treatment to achieve both curability and maintenance of quality of life. The aim of this study was to evaluate the short-term safety of combining limited surgery with adjuvant CRT for T1 or T2 lower rectal cancer.

METHODS

This was a multicenter, single-arm, prospective phase II trial. Patients diagnosed with lower rectal or anal canal cancer (clinical T1 or T2 with a maximum diameter of 30 mm and N0 and M0) underwent local excision or endoscopic resection. Patients received CRT with S-1 (tegafur/gimeracil/oteracil) after confirmation of well- or moderately differentiated adenocarcinoma, and negative margins, and/or depth of submucosal invasion ≥ 1000 µm or muscularis propria, and/or positive lymphovascular invasion, and/or tumor budding grade of 2/3. The primary endpoint was relapse-free survival. Secondary endpoints included overall and local relapse-free survival, safety, anal sphincter preservation rate, and anal function.

RESULTS

Pathological diagnosis was T1 in 36 patients and T2 in 16 patients. Serious complications after surgery were not reported. The CRT completion rate per protocol was 86.5% (45/52). Thirty-two patients developed 54 events of CRT-related adverse events, including only one patient with a grade 3 event (stomatitis). The most common CRT-related adverse event was diarrhea (n = 14). No patients showed deterioration of anal function at 3 years postoperatively.

CONCLUSION

CRT with S-1 after limited surgery for T1 or T2 lower rectal cancer resulted in a low incidence of toxicities and maintenance of anal function.

Sarcopenia is related to poor prognosis in patients after trimodality therapy for locally advanced non-small cell lung cancer

BACKGROUND

The association between sarcopenia and prognosis in patients with locally advanced non-small cell lung cancer (NSCLC) undergoing trimodality therapy, consisting of preoperative concurrent chemoradiotherapy and surgery, has not been reported. Therefore, we aimed to investigate the association of sarcopenia and fat mass with prognosis after trimodality therapy.

METHODS

To assess sarcopenia, the psoas muscle mass was measured. Using computed tomography data, including third lumbar vertebra level images, psoas muscle mass and visceral and subcutaneous fat mass were measured. Additionally, body mass indices, and visceral/subcutaneous fat ratio, obtained by dividing the visceral fat index by the subcutaneous fat index, were calculated. We investigated the relationship between these parameters and overall survival.

RESULTS

Ninety-nine eligible patients were included. In the univariate analysis, age, clinical stage, tumor location, psoas muscle index, and visceral/subcutaneous fat ratio were significant prognostic factors for overall survival (P = 0.008, P = 0.04, P = 0.04, P = 0.02, and P = 0.02, respectively). In the multivariate analysis, age and psoas muscle index were significant prognostic factors for overall survival (P = 0.01 and P = 0.03, respectively). The 5-year overall survival rates for the high and low psoas muscle index groups were 79.6% [95% confidence interval (CI), 67.1-94.5%] and 66.2% (95% CI, 54.1-81.1%), respectively; whereas, the 10-year overall survival rates were 61.9% (95% CI, 42.0-91.4%) and 25.3% (95% CI, 8.6-74.2%), respectively.

CONCLUSION

Sarcopenia was related to poor overall survival in patients with locally advanced NSCLC undergoing trimodality therapy. Assessment of body composition prior to treatment may provide important information for formulating rational therapeutic strategies.