Relationship between circulating tumour DNA and skeletal muscle stores at diagnosis of pancreatic ductal adenocarcinoma: a cross-sectional study

Muscle Loss During First-Line Chemotherapy Impairs Survival in Advanced Pancreatic Cancer Despite Adapted Physical Activity

BACKGROUND

Advanced pancreatic ductal adenocarcinoma (aPDAC) is often accompanied by significant muscle mass loss, contributing to poor prognosis. SarcAPACaP, an ancillary study of the GERCOR-APACaP phase III trial, evaluated the role of adapted physical activity (APA) in aPDAC Western patients receiving first-line chemotherapy. The study aimed to assess (1) the potential impact of computed tomography (CT)-quantified muscle mass before and during treatments on health-related quality of life (HRQoL) and overall survival (OS) and (2) the role of APA in mitigating muscle mass loss.

METHODS

In the APACaP trial, aPDAC patients with ECOG performance status (PS) 0-2 were randomized 1:1 to usual care including first-line chemotherapy or usual care plus a 16-week home-based APA program. In the SarcAPACaP study, the surface muscular index (SMI) was determined from L3 CT scan slices. Two patient populations were analysed: those with CT scan available at baseline (modified[m] intent-to-treat [ITT]1-W0) and those with CT scans available at both W0 and W16 (mITT2 W0-W16). Low muscle mass was defined by low SMI with SMI < 41 cm2/m2 for women and < 43 and < 53 cm2/m2 for men with body max index < 25.0 and ≥ 25.0 kg/m2, respectively. Muscle loss was defined by the relative difference of SMI between W0 and W16 (100*[SMI W16-SMI W0]/SMI W0). In mITT2 W0-W16, patients were stratified into three groups based on the severity of muscle loss: none, moderate (0%-10%) and high (≥ 10%). Associations between muscle mass loss and OS, time until definitive deterioration (TUDD) of HRQoL and the effect of APA on loss of muscle mass were assessed.

RESULTS

Between October 2014 and May 2020, 313 patients were prospectively enrolled, with 225 in mITT1 W0 and 128 in mITT2 W0-W16, with 65 assigned to the APA arm. Both groups had similar baseline characteristics with comparable OS and TUDD. A low SMI at W0 was not associated with OS and TUDD of HRQoL in either group. Among mITT2 W0-W16 patients, high muscle mass loss (n = 27) independently predicted OS (p = 0.012) and showed a trend toward negatively affecting TUDD of HRQoL. Notably, APA did not mitigate muscle loss in our study population.

CONCLUSIONS

Longitudinal muscle mass loss emerged as a predictive factor for both OS and HRQoL in aPDAC patients undergoing chemotherapy, while a low SMI at diagnosis did not provide prognostic value. APA did not impact muscle mass loss in this population.

Low Skeletal Muscle Radiodensity Predicts Response to CDK4/6 Inhibitors Plus Aromatase Inhibitors in Advanced Breast Cancer

BACKGROUND

Recent evidence indicates that a dysregulated host metabolism influences treatment outcomes in patients with breast cancer. We investigated the association of computed tomography (CT)-derived body composition indices with therapeutic responses in patients with hormone receptor-positive, HER2-negative advanced breast cancer (ABC) on endocrine plus CDK4/6 inhibitor (CDK4/6i) treatment.

METHODS

The study involved a retrospective cohort of patients with ABC at the Yonsei Cancer Center who received CDK4/6i and aromatase inhibitors as first-line therapy between January 2017 and October 2020. Body composition parameters were estimated from the non-enhanced CT images of the third lumbar spine by commercialized deep learning software. Patients with low skeletal muscle radiodensity (SMD) were defined as patients with SMD of low tertile (≤ 28.7 Hounsfield Units). The primary outcome was progression-free survival (PFS).

RESULTS

Among the 247 female participants (median age, 53 years; mean body mass index [BMI], 23.7 kg/m2), 45.7% had disease progression or death during a median follow-up of 36.4 months. After adjusting for age and visceral metastasis, SMD was the only independent predictor among body composition parameters for worse PFS (adjusted hazard ratio [HR] = 1.20 per standard deviation decrement, 95% CI: 1.01-1.42, p = 0.041), whereas BMI, muscle area, and fat area were not. Participants with low SMD had a higher risk of progression than those without (PFS, 27.2 vs. 51.1 months, p = 0.009; adjusted HR 1.84, 95% CI: 1.22-2.76, p = 0.003). Strong associations between low SMD and poor PFS were observed in groups with pre-menopause status (HR, 3.04 vs. 1.19 in post-menopause; 95% CI: 1.54-5.99, p for interaction < 0.05) and without visceral metastases (HR, 2.95 vs. 1.19 in with visceral metastases; 95% CI: 1.59-5.49, p for interaction < 0.05).

CONCLUSIONS

CT-defined low SMD predicts poor treatment outcomes in patients with ABC undergoing first-line treatment with aromatase inhibitors and CDK4/6i.

Factors associated with variability in skeletal muscle radiodensity in patients with metastatic cancer

OBJECTIVES

This study aimed to explore factors associated with skeletal muscle radiodensity (SMD) variability in patients with metastatic cancer.

METHODS

This study included 393 patients (median age 61 y, 70% women) who had computed tomography (CT) scans within 30 days of inclusion in the study. SMD was evaluated from CT by averaging the Hounsfield unit value of the total muscle area. Skeletal muscle index (SMI), visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and total adipose tissue index (TATI) were also assessed by CT. Additionally, age, sex, race/skin color, disease characteristics, comorbidities, inflammatory markers, handgrip strength (HGS), and body mass index (BMI) were recorded and evaluated in the linear regression analysis to identify factors associated with SMD variability.

RESULTS

Multivariate explanatory models having SMD as an independent variable were performed and included BMI (model 1, r2 = 0.699), TATI (model 2, r2 = 0.712) or VATI and SATI (model 3, r2 = 0.706) in addition to age, race/skin color, tumor site, kidney disease, serum albumin, HGS, and SMI as dependent variables. For all models, lower SMD was associated with higher age, BMI, and adiposity measurements, kidney disease, White race/skin color, and lower serum albumin, HGS, and SMI. The primary tumor site also contributed to changes in SMD in all models, specifically those located in the gastrointestinal tract, gynecologic, and bone and connective tissue.

CONCLUSION

In this group of patients with metastatic cancer, lower SMD was associated with older age, White race/skin color, and an overall worse clinical condition.

Circulating Tumor DNA Is an Accurate Diagnostic Tool and Strong Prognostic Marker in Pancreatic Cancer

OBJECTIVE

The objectives of the study are to investigate the sensitivity and specificity of circulating tumor DNA (ctDNA) for the diagnosis of pancreatic cancer and to assess the utility of ctDNA as a prognostic marker in this disease.

METHODS

Cell-free DNA was extracted from plasma of patients who underwent endoscopic ultrasound fine-needle aspiration or surgical resections for pancreatic cancer. The cell-free DNA was then analyzed using droplet digital polymerase chain reaction for KRAS G12/13 mutations. Eighty-one patients with pancreatic cancer and 30 patients with benign pancreatic disease were analyzed.

RESULTS

ctDNA KRAS G12/13 mutations were detected in 63% of all patients with pancreatic cancer and in 76% of those patients who also had KRAS G12/13 mutations detected in the pancreatic primary. Specificity and tissue concordance were both 100%. Circulating tumor DNA corresponded with tumor size and stage, and high ctDNA was associated with significantly worse prognosis on both univariate and multivariate testing.

CONCLUSION

Our study shows that ctDNA is an accurate diagnostic tool and strong prognostic marker in patients with pancreatic cancer. The continued investigation of ctDNA will enable its implementation in clinical practice to optimize the care and survival outcomes of patients with pancreatic cancer.