Preoperative versus postoperative chemo-radiotherapy for locally advanced gastric cancer: a multicenter propensity score-matched analysis

Who would be the winner? A prognostic nomogram for predicting the benefit of postoperative radiotherapy ± chemotherapy in patients with locally advanced gastric cancer: TROD-02-01 study

OBJECTIVES

We aimed to develop a basic, easily applicable nomogram to improve the survival prediction of the patients with stage II/III gastric cancer (GC) and to select the best candidate for postoperative radiotherapy (RT).

METHODS

In this multicentric trial, we retrospectively evaluated the data of 1597 patients with stage II/III GC after curative gastrectomy followed by postoperative RT ± chemotherapy (CT). Patients were divided into a training set (n = 1307) and an external validation set (n = 290). Nomograms were created based on independent predictors identified by Cox regression analysis in the training set. The consistency index (C-index) and the calibration curve were used to evaluate the discriminative ability and accuracy of the nomogram. A nomogram was created based on the predictive model and the identified prognostic factors to predict 5-year cancer-specific survival (CSS) and progression-free survival (PFS).

RESULTS

The multivariate Cox model recognized lymph node (LN) involvement status, lymphatic dissection (LD) width, and metastatic LN ratio as covariates associated with CSS. Depth of invasion, LN involvement status, LD width, metastatic LN ratio, and lymphovascular invasion were the factors associated with PFS. Calibration of the nomogram predicted both CSS and PFS corresponding closely with the actual results. In our validation set, discrimination was good (C-index, 0.76), and the predicted survival was within a 10% margin of ideal nomogram.

CONCLUSIONS

In our relatively large cohort, we created and validated both CSS and PFS nomograms that could be useful for underdeveloped or developing countries rather than Korea and Japan, where the D2 gastrectomy is routinely performed. This could serve as a true map for oncologists who must make decisions without an experienced surgeon and a multidisciplinary tumor board.

Role of Preoperative Radiation Therapy for Resectable Gastric Cancer

PURPOSE

While surgery is the primary curative treatment for resectable gastric and gastroesophageal junction (GEJ) cancer, rates of locoregional and distant recurrence remain high with surgery alone, especially in more advanced disease. Multimodal approaches with perioperative therapy including chemotherapy and/or radiation therapy (RT) have thus evolved as ways to reduce the rates of disease recurrence and improve survival outcomes. This review article provides a comprehensive literature review on the role of preoperative RT for resectable gastric and GEJ cancer.

METHODS

A literature review on the role of preoperative RT for resectable gastric and GEJ cancer was conducted.

RESULTS

Preoperative RT has the potential to facilitate tumor downstaging and improved R0 resection, allowing for better locoregional control and thereby survival. For resectable locally advanced GEJ cancer, preoperative chemoradiotherapy (CRT) is currently a standard of care option along with perioperative chemotherapy, based on evidence from randomized trials. In resectable gastric cancer, however, the role of preoperative CRT is less defined with no randomized data to date, although phase II single-arm studies have shown promising results. Current standard of care for gastric cancer remains perioperative chemotherapy, with consideration for preoperative CRT in select cases.

CONCLUSION

Results from ongoing and future randomized controlled trials are expected to help define the role of preoperative CRT compared to perioperative chemotherapy alone as well as postoperative CRT for gastric and GEJ cancer.

Survival Benefit of Induction Chemotherapy with Paclitaxel and Carboplatin Followed by Chemoradiation Versus Postoperative Treatment in Locally Advanced Gastric Cancer: A Retrospective Cohort Study

BACKGROUND

Gastric cancer remains a prevalent worldwide illness that lacks a definitive cure. Recently, induction chemotherapy followed by concurrent chemoradiation has shown promising results in achieving a significant pathological response in locally advanced gastric cancer and improving survival rates. However, the optimal regimen for this approach continues to be a subject of discussion.

METHODS

This retrospective cohort study was conducted on treatment-naïve patients with locally advanced gastric cancer who were referred to Imam Hossain General Hospital in Tehran, Iran, between April 2016 and March 2019. Eligible patients met the criteria of clinical T3-4 or nodal-positive stage, or both, and had non-metastatic resectable tumors. The patients were categorized into two groups: (a) the neoadjuvant group, which received induction chemotherapy (carboplatin AUC 2 and paclitaxel 50 mg/m2 weekly for 12 cycles) followed by concurrent neoadjuvant chemoradiation (radiotherapy 45-50 Gy/1.8 Gy per fraction concurrent with capecitabine 500 mg/m2 BID and oxaliplatin 40 mg/m2 weekly), and (b) the adjuvant group, which was treated with standard chemoradiation or chemotherapy regimens. The two groups were compared regarding the 3-year recurrence rate and 3-year overall survival.

RESULTS

A total of 102 patients were included in the study (63.7% male, mean age ± standard deviation 56 ± 13 years). Among these, 45 patients received neoadjuvant treatment, and 57 received adjuvant treatment. The neoadjuvant group had a higher proportion of patients with advanced disease (stage III: 91.1% vs. 57.9%, P = 0.001). In the neoadjuvant group, 20 patients (44.4%) achieved a complete pathologic response, and all underwent curative surgery. The neoadjuvant group exhibited a lower 3-year recurrence rate (13 [28.9%] vs. 33 [57.9%], P = 0.003) and a higher 3-year overall survival rate (36 [80%] vs. 32 [56.1%], P = 0.003).

CONCLUSIONS

Patients receiving induction chemotherapy with paclitaxel and carboplatin followed by chemoradiation demonstrated enhanced disease control and survival compared to standard adjuvant regimens. In addition, patients treated with the applied preoperative regimen in this study showed higher pathologic response and overall survival rates than in previous studies.

Neoadjuvant versus adjuvant radiotherapy for resectable locally advanced gastric cancer: A SEER population analysis

Background

There is a lack of evidence on whether resectable locally advanced gastric cancer (LAGC) patients could benefit from neoadjuvant or adjuvant radiotherapy (RT).

Methods

Patients with surgically diagnosed LAGC from 2004 to 2015 were retrieved from the SEER database. Kaplan-Meier method and the log-rank test were used to evaluate survival analysis between neoadjuvant and adjuvant RT. Univariate Cox regression was used to evaluate the hazard ratio (HR) and 95 % confidence interval (CI).

Results

A total of 4790 LAGC patients who treated with surgery and RT were identified, including 3187 patients with intestinal subtype and 1603 patients with diffuse subtype. For patients with both intestinal and diffuse subtypes, median cancer-specific survival (mCSS) was better with adjuvant RT or neoadjuvant RT. Moreover, patients benefited more from adjuvant RT than neoadjuvant RT (intestinal subtype: mCSS 49 vs. 36 months, P < 0.001; diffuse subtype: mCSS 32 vs. 26 months, P = 0.050). Further analyses showed that patients with intestinal subtype and T1-2N+, T3N-, T3N+ subgroups, as well as patients with diffuse subtype and T1-2N+ and T3N+ subgroups benefited more from adjuvant RT than those with neoadjuvant RT. Patients in the diffuse subtype and T3N- subgroups also tended benifit from adjuvant RT and survive. There was no difference in survival between the T4N- and T4N + subgroups of the two subtypes. After propensity score matching, subgroup analysis identified an improved survival in favor of adjuvant RT in the age ≥65 years and female subgroups in diffuse subtypes and T4N+ patients.

Conclusions

For patients with resectable LAGC in the T1-2N+, T3N-, T3N+ clinical subgroups, adjuvant RT yields more benefits than neoadjuvant RT or no RT, which is worthy of prospective clinical trial.

Surgery for locally advanced gastric cancer in the era of neoadjuvant therapies: something new?

BACKGROUND

Locally advanced gastric cancer (LAGC) represents a therapeutic challenge, particularly as it often involves adjacent organs. The necessity of neoadjuvant treatments for LAGC patients is still controversial. The aim of this study was to analyze the factors affecting prognosis and survival in patients with LAGC with particular regard to the effect of neoadjuvant therapies.

METHODS

Between January 2005 and December 2018, the medical records of 113 patients with LAGC who underwent curative resection were retrospectively reviewed. Patient characteristics, related complications, long-term survival, and prognostic factors were analyzed at uni- and multivariate analyses.

RESULTS

Postoperative mortality and morbidity rates of patients undergoing neo-adjuvant therapies were 2.3% and 43.2%, respectively. Whereas in patients undergoing upfront surgery were 4.6% and 26.1%, respectively. R0 resection was achieved 79.5% and in 73.9% of patients undergoing neoadjuvant therapy and upfront surgery, respectively (P<0.001). Multivariate analysis revealed that neoadjuvant therapy, completeness of resection (R0), number of lymph nodes retrieved, N status and the adoption of hyperthermic intraperitoneal chemotherapy were independent prognostic factors associated with longer survival. Five-year overall survival for NAC group and upfront surgery group was 46% and 32%, respectively (P=0.04). Five-year disease-free survival for NAC group and upfront surgery group was 38% and 25%, respectively (P=0.02).

CONCLUSIONS

Patients with LAGC undergoing surgery plus neoadjuvant therapy had a better OS and DFS with respect to patients treated with surgery alone.