Role of Positron Emission Tomography/Computed Tomography Findings for Adjuvant Chemotherapy Indications in Stage T1b-2aN0M0 Lung Adenocarcinoma

The prediction of spread through air spaces with preoperative 18F-FDG PET/CT in cases with primary lung adenocarcinoma, its effect on the decision for an adjuvant treatment and its prognostic role

PURPOSE

In lung adenocarcinoma cases, 'spread through air spaces' (STAS) is a new indicator of invasion and directly related to disease survival. The aim of our study is to establish whether a preoperatively performed 18F-Fluorodeoxyglucose (FDG) PET/computed tomography (CT) imaging data can predict the presence of STAS in cases with lung adenocarcinoma and thus predict the decision for the type of surgery and adjuvant chemotherapy.

MATERIALS AND METHODS

Between 2000 and 2019, we retrospectively analyzed 63 patients with lung adenocarcinoma cases that had undergone lobectomy or pneumonectomy. Semiquantitative parameters were calculated and metabolic tumor volume (MTV)/CT volume (CTV) ratio was recorded from FDG PET/CT data. The pathological samples from these patients were evaluated for STAS. All these values were evaluated for their correlation with the alveolar spread.

RESULTS

There was no statistically significant correlation to be found between CTV, MTV, total lesion glycolysis (TLG), standardized uptake value (SUV)max, SUVmean and STAS (P > 0.05). However, MTV/CTV ratio above 1 had statistically more alveolar spread. In the group with an MTV ratio above 1, STAS positivity was 27 (75%), and 9 (25%) did not have STAS, whereas these were 6 (22.2%) patients who had STAS, and 21 (77.8%) did not have STAS in the group with below 1 (P < 0.001).

CONCLUSIONS

In the preoperative PET study inoperable lung adenocarcinoma cases, MTV/CTV ratio higher than 1 was found to predict STAS positivity. As a result, it was found that it provided significant clinical additional information regarding the need for a surgical approach (lobar resection instead of sublobar) and adjuvant chemotherapy.

Combining fluorine-18 fluorodeoxyglucose positron emission tomography and pathological risk factors to predict postoperative recurrence in stage I lung adenocarcinoma

OBJECTIVE

The aim of this study was to investigate the predictive value of qualitative assessment of tumor fluorine-18 fluorodeoxyglucose (F-FDG) uptake on PET and pathological risk factors for postoperative tumor recurrence in patients with stage I lung adenocarcinoma.

PATIENTS AND METHODS

Eighty-seven patients with stage I lung adenocarcinoma who had undergone F-FDG-PET and sequential surgical treatment without adjuvant chemotherapy were enrolled into this retrospective study. Qualitative assessment visually compared tumor F-FDG uptake with liver uptake. Tumors with one or more risk factors of tumor size of at least 4 cm, poorly differentiated, visceral pleural invasion, and lymphovascular invasion were defined as pathological high-risk tumors.

RESULTS

Patients with pathological high-risk tumors had a significantly (P=0.015) higher standardized uptake value. A multivariable Cox's proportional hazard analysis showed that tumor F-FDG uptake>liver uptake (adjusted hazard ratio: 3.54; 95% confidence interval: 1.36-9.21, P=0.010) and pathological high-risk tumors (adjusted hazard ratio: 2.34; 95% confidence interval: 1.13-4.87, P=0.023) were significant independent predictors of postoperative tumor recurrence. Patients with tumor F-FDG uptake>liver uptake and pathological high-risk tumors had significantly (P=0.001) worse 5-year disease-free survival (38.8%) and significantly (P=0.011) worse overall survival (68.5%).

CONCLUSION

Tumor F-FDG uptake>liver uptake and pathological high-risk tumors were significant independent predictors of postoperative tumor recurrence in stage I lung adenocarcinoma. Combining the two factors improves the prediction of disease-free and overall survivals, which could offer a feasible prediction model for clinically recommending adjuvant chemotherapy.

The prognostic value of tumor shadow disappearance rate on integrated PET/CT evaluation of solitary pulmonary nodules with low glucose metabolism

OBJECTIVE

This study aimed to determine the prognostic value of the tumor shadow disappearance rate (TDR) on integrated PET/computed tomography (PET/CT) evaluation of solitary pulmonary nodules (SPNs) with low glucose uptake.

MATERIALS AND METHODS

From January 2008 to September 2010, 99 patients who underwent fluorine-18 fluorodeoxyglucose PET (F-FDG-PET)/CT scanning for the evaluation of SPNs with a maximum standardized uptake value (SUVmax) below 2.75 (2.5+10%) were retrospectively reviewed. Among the 99 SPNs from these patients, 67 were malignant and 32 were benign, based on surgical pathology. Differences in baseline characteristics between the two groups were examined by means of the independent t-test, the Mann-Whitney U-test, and the χ-test. To test the efficacy of TDR for determining malignancy, the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and positive and negative likelihood ratios (LR+ and LR-, respectively) with 95% confidence intervals were calculated using the pathological test as the gold standard.

RESULTS

Patients with malignant nodules were older than those with benign nodules (64.5 vs. 55.1 years, respectively, P<0.001) and had higher TDRs (0.8 vs. 0.3, respectively, P<0.001). The optimal cutoff point for the TDR was 0.4886 where the sensitivity, specificity, positive predictive value, and negative predictive value were 0.851, 0.844, 0.919, and 0.730, respectively, and the LR+ and LR- were 5.443 and 0177, respectively. A significant negative correlation between TDR and SUVmax was found only in the malignant group.

CONCLUSION

The diagnostic value of TDR complements the PET/CT evaluation of SPNs with a low F-FDG uptake.

Impact of Lepidic Component Occupancy on Effects of Adjuvant Chemotherapy for Lung Adenocarcinoma

BACKGROUND

The prognosis of lepidic predominant lung adenocarcinoma is favorable. We postulated that lepidic predominant tumors might not require postoperative adjuvant chemotherapy. The present study aims to determine whether lepidic component occupancy affects overall survival after postoperative adjuvant chemotherapy for lung adenocarcinoma.

METHODS

Clinical and pathologic data were collected from a database and from the medical records of 964 patients with completely resected lung adenocarcinoma. We assessed the influence of lepidic component occupancy in the tumor on the outcomes of adjuvant chemotherapy.

RESULTS

Among the patients, 270 received adjuvant chemotherapy and 694 did not, and 415 and 549 had lepidic predominant and non-lepidic predominant tumors, respectively. Adjuvant chemotherapy contributed to better overall survival compared with observation in non-lepidic predominant tumors (p = 0.025). Multivariate analyses revealed age, sex, stage, lepidic component occupancy, and adjuvant chemotherapy as independent prognostic factors for overall survival. The overall survival was significantly longer for patients with non-lepidic predominant tumors at stages IA, IB, and II-III under adjuvant chemotherapy compared with observation (p = 0.040, p = 0.007, and p = 0.012, respectively), whereas survival rates were similar for patients with all stages of lepidic predominant tumors even after propensity score matching study.

CONCLUSIONS

Lepidic component occupancy reflected the effect of adjuvant chemotherapy for lung adenocarcinoma. Adjuvant chemotherapy did not have much impact for lepidic predominant tumors and could be considered for non-lepidic predominant tumors even at stage IA.

[Progress of Postoperative Adjuvant Chemotherapy in Stage I Non-small Cell Lung Cancer]

The morbidity and mortality of lung cancer rank the first place among all the malignant tumor. According to the histopathological characteristics, lung cancer is divided into non-small cell lung cancer (NSCLC) and small cell lung cancer. Only 20% patients diagnosed with NSCLC have the chance for surgery while their 5-yr overall survival is about 30%-60%. The therapeutic outcome of surgery alone is not satisfying. Adjuvant chemotherapy after surgical resection in stage II-IIIa lung cancer showed efficacy in many randomized clinical trials, but its role in stage I disease remains controversial. The choice of appropriate chemotherapy candidates, the selection of chemotherapy regimens and the research progress on biomarker are mainly discussed in this review.