Advances in para-aortic nodal dissection in gastric cancer surgery: A review of research progress over the last decade

Para-Aortic Lymphadenectomy in Ovarian, Endometrial, Gastric, and Bladder Cancers: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Para-aortic lymphadenectomy can be used for both diagnostic and therapeutic purposes as it aids in staging, provides prognostic data, and influences the patient's options for adjuvant therapy. However, there is still contention over its potential in treating cancer. A systematic review of the literature was performed to look into the published randomized controlled studies (RCTs) that have reported the effectiveness of lymphadenectomy.

METHODS

Five different electronic databases, including PubMed, Cochrane Library, Clinical trials.gov, ICTRP, and Embase, were used to conduct a comprehensive search. Original RCTs reporting on the impact of lymphadenectomy on the overall survival in various cancers were included. Information related to the study population, intervention, type of cancer, primary endpoints, and key findings of the study were extracted. Quality assessment of the selected studies was conducted using the Revised Cochrane Risk of Bias Tool Rob 2 for randomized trials.

RESULTS

A total of 1693 citations, with 1511 from PubMed, 80 from the Cochrane Library, 67 from Embase, 18 from ICTRP, and 17 from Clinicaltrials.gov were retrieved. Preliminary screening was performed, and after applying selection criteria, nine articles were included in the final qualitative analysis. The total number of patients was 4231, and the sample size ranged from 70 to 1408. Among these nine studies, four studies were on genital cancers (two ovarian cancers, one endometrial cancer, and one cervical cancer); four on digestive cancers (advanced gastric cancers); and one on urinary cancer (advanced bladder cancer). These studies reported that para-aortic lymphadenectomy did not improve overall survival and disease-free survival in advanced ovarian cancers, early endometrial cancers, advanced gastric, and bladder cancers. All of the studies had a low risk of bias.

CONCLUSIONS

Para-aortic lymphadenectomy is not advised in advanced ovarian cancers, early endometrial cancers with low risks, advanced gastric cancers, and bladder cancers. SNB could be an alternative to lymphadenectomy for ovarian cancer in the future. Clinicians should inform patients regarding the benefits of para-aortic lymphadenectomy in terms of survival and the potential risks associated with it.

A phase II study of perioperative treatment in gastric cancer with No.16a2/b1 lymph node metastasis: DRAGON-06 trial

Although gastric cancer with para-aortic lymph node (PAN) metastasis is commonly regarded as unresectable, surgeons have explored the optimal treatment for patients with PAN metastases limited to No.16a2/b1 in the past few decades. Preoperative systemic therapy combined with D2 gastrectomy plus PAN dissection may improve the prognosis of these patients. In this multicenter phase II trial, 29 gastric cancer patients with PAN metastasis limited to No.16a2/b1 will receive preoperative treatment with nab-paclitaxel, oxaliplatin, S-1 (nab-POS: nab-paclitaxel, oxaliplatin, S-1) and sintilimab followed by D2 gastrectomy plus PAN dissection; and postoperative treatment with oral S-1, intravenous sintilimab and intraperitoneal paclitaxel. The end points for the study are 3-year overall survival, 3-year disease-free survival, pathological response rate, incidence of postoperative complications and adverse events.

Long-Term Outcomes of Surgical Resection of Pathologically Confirmed Isolated Para-Aortic Lymph Node Metastases in Colorectal Cancer: A Systematic Review

BACKGROUND

Para-aortic lymph node (PALN) metastases represent patterns of initial recurrence in only 2-6% CRC patients, after an estimated 23-28 month time interval. An increasing trend towards curative surgery has been witnessed in patients presenting with controlled PALN recurrence. Nevertheless, lack of consensus has impaired an unambiguous statement for PALN recurrence resection.

METHODS

We performed a systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) guidelines, which led us to gain deeper insight into the prognostic factors and long-term outcomes after resection for synchronous or metachronous pathologically confirmed CRC isolated para-aortic lymph node metastases (PALNM). Pubmed/MEDLINE, Embase, Scopus, Cochrane Library and Web of Science databases were used to search all related literature.

RESULTS

The nine articles included covered a study period of 30 years (1988-2018), with a total of 161 patients. At presentation, most primary CRCs were located in the colon (74%) and 95.6%, 87.1% and 76.9% patients had T3-T4, N1-N2 and well/moderately differentiated CRC, respectively. We identified a 59.4-68% 3-year OS rate and 53.4-87.5% 5-year OS rate, with a 25-84 months median OS, 26.3-61% 3-year DFS rate and 0-60.5% 5-year DFS rate, with a 14-24 month median DFS. Overall, 62.1% re-recurrence rate ranged from 43.8% to 100%.

CONCLUSIONS

Although PALNMs resection in CRC patients may be considered a feasible and beneficial option, no conclusions or recommendations can be made taking into account the current evidence. Therefore, further randomized, possibly multicenter trials are strongly recommended and mandatory if we want to have our results confirmed and patient selection criteria clearly identified.

Successful laparoscopic conversion surgery for gastric cancer with para-aortic lymph node metastasis after third-line chemotherapy: a case report

We herein reported a case of advanced gastric cancer (GC) with para-aortic lymph node (PALN) metastases who successful achieved downstaging following systemic chemotherapy and underwent curative laparoscopic conversion surgery. A 74-year-old male patient diagnosed with advanced GC and PALN metastases [cT4N3M1(LYM), stage IVA] was administered chemotherapy and immunotherapy for 28 months. After 27 courses of nivolumab as third-line chemotherapy, PALN enlargement was resolved, for which conversion surgery was planned. Subsequently, laparoscopic distal D2 gastrectomy with sampling para-aortic lymphadenectomy was performed, after which a pathological diagnosis of type V moderately differentiated tubular adenocarcinoma with mucinous adenocarcinoma, stage ypT3 (SS), ly1c, and v0, was established. The pathological proximal and distal tumor margins were negative. One lymph node metastasis was observed (No. 6; 1/25). The sampled lymph nodes were negative (No. 16a1: 0/2). The therapeutic effect was categorized as Grade 1a. The postoperative course was uneventful, with the patient receiving nivolumab to control for potential PALN metastases. Postoperatively, no recurrence was observed over 11 months. Laparoscopic conversion gastrectomy was successfully performed in a patient with advanced GC that was originally unresectable, suggesting that minimally invasive surgery may be a good option for originally unresectable advanced GC that becomes resectable.

D2 vs D2 Plus Para-aortic Lymph Node Dissection for Advanced Gastric Cancer

Objectives

Gastric cancer is a common malignancy worldwide. Effective treatment by interdisciplinary cooperation is important, and surgery still plays an important role.

Material and Methods

In a ten-year period, 355 patients were diagnosed to have gastric cancer. One hundred and sixty-two patients with a median (range) age of 58 (23-83) years were eligible for the study. There were 107 patients in D2 and 55 patients in D2 lymphadenectomy plus para-aortic lymph node (PALN) dissection group. The two groups were compared in terms of complications, morbidity, mortality and long-term survival.

Results

Length of stay was 12 (8-34) days for D2 and 14 (8-42) days for D2 plus PALND. Total number of operative mortality was 8/162 (5%), and it was not different between the groups. Twenty patients (18%) had complications in D2 group and 9 (17%) patients in D2 plus PALND group. Overall survival was also similar between the groups, but patients with T3-T4 tumors, patients with stage IIIA and IIIB disease had better survival with D2 plus PALN dissection. We found that the depth of invasion, PLN, ratio (PLN/TLN), stage and LND were all prognostic variables.

Conclusion

This study showed that D2 plus PALN dissection for advanced gastric cancer can be performed as safely as a standard D2 dissection by experienced surgeons without increasing postoperative morbidity and mortality. D2 plus PALN dissection should be preferred in the advanced stage of the disease (IIIA-IIIB) as it increases the rate of survival.

Current status of lymph node dissection in gastric cancer

Gastrectomy with lymph node (LN) dissection has been regarded as the standard surgery for gastric cancer (GC), however, the rational extent of lymphadenectomy remains controversial. Though gastrectomy with extended lymphadenectomy beyond D2 is classified as a non-standard gastrectomy, its clinical significance has been evaluated in many studies. Although hard evidence is lacking, D2 plus superior mesenteric vein (No. 14v) LN dissection is recommended when harbor metastasis to No. 6 nodes is suspected in the lower stomach, and dissection of splenic hilar (No. 10) LN can be performed for advanced GC invading the greater curvature of the upper stomach, and D2 plus posterior surface of the pancreatic head (No. 13) LN dissection may be an option in a potentially curative gastrectomy for cancer invading the duodenum. Prophylactic D2+ para-aortic nodal dissection (PAND) was not routinely recommended for advanced GC patients, but therapeutic D2 plus PAND may offer a chance of cure in selected patients, preoperative chemotherapy was considered as the standard treatment for GC with para-aortic node metastasis. There has been no consensus on the extent of lymphadenectomy for the adenocarcinoma of the esophagogastric junction (AEG) so far. The length of esophageal invasion can be used as a reference point for mediastinal LN metastases, and the distance from the esophagogastric junction to the distal end of the tumor is essential for determining the optimal extent of resection. The quality of lymphadenectomy may influence prognosis in GC patients. Both hospital volume and surgeon volume were important factors for the quality of radical gastrectomy. Centralization of GC surgery may be needed to improve prognosis.