Relationship between tumor infiltrating lymphocytes and clinicopathological features in Peruvian gastric cancer

e16080

Background: Role of tumor-infiltrating lymphocytes (TIL) over clinicopathological features including Mismatch Repair (MMR), HER2 status, Epstein Barr Virus (EBV) and Helicobacter pylori (HP) infection is not well understood in gastric cancer (GC). Methods: TIL level and HP infection was also evaluated in H&E from 503 Peruvian GC patients who underwent surgery. Density of CD3+ T cells, CD8+ cytotoxic T cells, CD163 M2 macrophages, as well as MMR and HER2 status were determined by immunohistochemistry. HP and EBV infection was also detected by qPCR in a 234 cases subset. Results: Median age was 62 years and 50.1% were female, most tumors were grade 3 (59.1%), intestinal subtype (44.8%) and stage III (59.8%). MMR loss was found in 29.4% and HER2+ in 4.7%. HP+ was detected by H&E in 55.7% and by qPCR in 63.7%. EBV+ by qPCR was found in 20.5% and co-infection along with HP in 9.4% (22/234). Stage (p < 0.001), intestinal histology (IH) (p = 0.019), grade (p = 0.006) and lymphovascular invasion (p < 0.001) were associated with longer survival. Median TIL was higher in invasive border (IB) and stromal (ST) than intratumoral (IT) compartment but there were significantly correlated (p < 0.001). High IT TIL was associated with absence of HP H&E (p = 0.009). High ST TIL was associated with older age (p < 0.001), IH (p < 0.001), grade 1 (p = 0.009), lower stage (p = 002), MMR loss (p = 0.019) and EBV+ (p = 0.001). Density of CD3 and CD8 were significantly correlated in IT and ST compartments (p < 0.001). High CD3 density in IT compartment was associated with grade 3 (p = 0.001) and HP- (p = 0.02), and in ST was associated with IH (p = 0.005), grade 1- 2 (p = 0.002) and MMR loss (p = 0.04). High IT CD8 was associated with HER2- (p = 0.016), HP- (p = 0.014) and EBV+ (p = 0.012). High ST CD8/CD3 ratio was associated with diffuse histology (p = 0.034), grade 3 (p = 0.013), more advanced stage (p = 0.022) and recurrence (p = 0.014). High ratio of IT CD8/CD3 was associated with MMR loss (p = 0.007). High ST TIL was associated with longer DFS (p = 0.007). Lower ratio of CD8/CD3 was associated with longer OS (p = 0.024) and DFS (p = 0.02). Conclusions: TIL levels and infiltrating immune subpopulations differs by clinicopathological features in GC including MMR loss, HER2 expression EBV and HP infection. ST CD8/CD3 was associated with recurrence and shorter DFS.

Open versus minimally invasive sphincter-sparing surgery for rectal cancer: a single-center retrospective cohort study in Peru

OBJECTIVE

The study aimed to describe and compare minimally invasive surgery (MIS) and open surgery for rectal cancer in Peru.

MATERIAL AND METHODS

A retrospective single-center analysis was performed for all patients who underwent sphinctersparing surgery for non-metastatic rectal cancer at Instituto Nacional de Enfermedades Neoplásicas in Peru between January 2016 and December 2020. Clinical, perioperative, pathological, and survival outcomes were compared between both groups. A propensity score matching method was used to minimize bias.

RESULTS

162 patients were included in the final analysis. 124 had open surgery and 38 had MIS. Patients, clinical tumour, pathological characteristics, and perioperative were similar between groups after matching. Similar circumferential resection margin (CRM) with optimal quality of the mesorectum (p=1.000) but higher number of lymph nodes resected in open surgery group (p=0.741) was described. The leakage rate was slightly higher in the MIS group (p=0.358) with 10.5%, while the postoperative hospital stay was longer in the open surgery group after matching (p=0.001; OR 95% 5.2 CI: 1.8-15.6). The estimated recurrence-free survival (RFS) and overall survival (OS) at 3 years in open surgery and MIS was 71.8% (95% CI; 0.58-0.89) and 70% (95% CI; 0.56-0.88) (p=0.431) and 77.7% (95% CI; 0.64-0.94) and 88.9% (95% CI; 0.79-0.99) (p=0.5), respectively.

CONCLUSIONS

Shorter postoperative hospital stay in the minimally invasive surgery group was reported. RFS, OS, and recurrence rates were similar between both groups. This approach is for non-metastatic rectal cancer in referral centers in Peru.

bghcng

e15521

Background: Helicobacter pylori (HP) infection is one of the most common infections worldwide and is a risk factor for gastric cancer (GC) development. This study was conducted to determinate the prevalence rate of HP as well as presence of vacA and cagA in gastric cancer samples from Peruvian patients. Methods: GC samples were prospectively collected from patients who went to surgery between April 2015 and November 2016. Three types of gastric samples were obtained from each patient: tumoral area (T), proximal healthy (P) and distal healthy tissue (D) samples. HP status through H&E was analyzed by a pathologist. DNA was extracted from tissue, and detection of colonization (ureA and hspA) and virulence genes (vacA and cagA) of HP was performed through quantitative PCR (qPCR). Results: A total of 183 patients were studied with a mean age of 64 years and 51.9% were men. 52.2% had a primary from antrum, 47.8% was HG 3 and 60% were diffuse. Presence of HP through H&E was found in 58.4% (n=107/183). Positive HP cases through qPCR were determinate with positivity of at least one ureA/hspA gene and was found in 89.6% (n=164/183). HP detection rate and its concentration were higher in D (ureA: 62.8%, n=115, [703.58±245.47pg]; hspA: 73.8%, n=135, [42.77±10.17pg]) than P (ureA: 59.0%, n=108, [539.69±121.32pg]; hspA: 71.0%, n=130, [31.90±8.64pg]) and T (ureA: 49.7%, n=91, [296.32±164.98pg]; hspA: 70.5%, n=129, [4.6±1.33pg]) (p<.001). Antrum location was associated to higher level of hspA expression (p=0.047). Neither histology (p=0.45) nor HG (p=0.2) was associated to level of hspA expression. qPCR detected HP in 75% (n=57/76) of cases without evidence of HP by pathology evaluation (H&E) (ICC: 0.77 vs 0.58). cagA virulence gene was detected in 95.8% (n=159/166) while vacAm allele in 85.5% (n=142/166) and vacAs allele in 96.8% (n=160/166). vacA+cagA- combination was found in 0.6% (n=1/166), vacA+cagA+ cases in 95.8% (n=159/166) and vacA-cagA- cases in 3.6% (n=3/166). Conclusions: Our results show a significant presence of HP in Peruvian gastric cancer patients and combination of vacA+/-cagA+/- virulence genes had particular patterns.

Oncological outcomes in extended intervals time betweeen preoperative chemoradiation with capecitabine and surgery in operable rectal adenocarcinoma: Experience at the National Cancer Institute of Peru

e15158

Background: The literature reports that longer interval between the end of neoadjuvantchemoradiotherapy (CRT) and surgery is associated with a better rate of pathologic complete response (pCR) in rectal cáncer. Optimal interval remains to be defined. The effects of the extended time intervals on the prognosis are not clear. The objective was to assess whether extended time intervals ( < 8, 8-12, > 12-20 and > 20 weeks) between the end of neoadjuvant CRT and surgery improve overall survival (OS), disease-free survival (DFS) and pathological outcomes Methods: Aretrospective study was conducted for 124 patients with rectal adenocarcinoma without evidence of metástasis (T1-4/N0-2/M0) at the time of diagnosis that underwent surgery with curative intent after neoadjuvant CRT with capecitabine and obtained R0 or R1 resection between January 2010 to December 2014 at National Cancer Institute of Peru. Patients undergoing emergency surgery and R2 resection have been excluded. Survival curves were calculated according to Kaplan-Meier method and compared with log-rank test Results: Of the 124 patients, 72 were women (58.1%). The average age was 59.5 years. All received neoadjuvant CRT. Rates of pCR in the four groups were 25.0%, 10.3%, 7.7% and 17.2%, respectively. No significant difference was found between the association of the radial (P = 0.418) and distal edge (P = 0.487), with time interval groups and similarly with resected (P = 0.308) and compromised nodules (p = 0.783). The median OS follow-up time was 39.5 months and for DFS was 34 months. No significant differences were observed in OS (p = 0.739) and DFS (p = 0.902) according to the four groups studied. Conclusions: We found that amplifying the time interval at 31.9 weeks did not change the mean radial and distal edge. It does not affect the mean of resected and compromised nodules and does not improve overall survival and disease-free survival. The present study is the only one that reports these results at these time intervals. It allows to extend the intervals of time for future studies that finally will define the best time interval for the surgery.

Fluorescence probes for prokaryotic and eukaryotic cells using Re(CO)3+complexes with an electron withdrawing ancillary ligand

Re(CO)₃⁺complexes with an ancillary ligand present an electron withdrawing effect suitable for cell imaging.

[Laparoscopic distal gastrectomy for gastric cancer: initial experience]

OBJECTIVE

To report the initial experience with the laparoscopy-assisted distal gastrectomy (LADG) with D2 lymphadenectomy for gastric cancer.

PATIENTS AND METHODS

Between May 2006 and May 2007, 29 consecutive GC patients with gastric cancer underwent LADG with D2 lymphadenectomy. The operation consisted in a laparoscopic time to perform lymphadenectomy and mobilization of the distal stomach, followed by a minilaparotomy for exteriorization of the specimen and construction of a hand sewn anastomosis.

RESULTS

Twenty-nine patients underwent LADG with D2 lymphadenectomy for gastric cancer. Mean age was 58.2 years. Mean operative time was 287.4 min. Mean number of lymph nodes resected was 42.6. Twelve patients were early gastric cancer, and seventeen were advanced gastric cancer. Mean proximal and distal resection margin were 5.8 cm and 3.5 cm, respectively. Resection margins were negative in all cases. Mean number of lymph nodes resected was 42.6. Thirty-day morbidity rate was 10.3 %. There were no postoperative deaths.CONCLUSION. The short-term results of our LADG with D2 lymphadenectomy for the treatment of gastric cancer shows that a radical surgery, in terms of resection margins and lymphadenectomy, can be done with low morbidity.

Effect of asymmetry on the electronic delocalization in diiron and iron-cobalt mixed valence metallocenic compounds

In this work, we report the synthesis and a study on the degree of electronic delocalization in the asymmetric mixed valence complexes [CpFe(C(8)H(6))Fe(C(8)H(7))](+), 3a(+), and [CpCo(C(8)H(6))Fe(C(8)H(7))](+), 3b(+), (Cp = C(5)Me(5), C(8)H(6) = pentalenyde, C(8)H(7) = hydropentalenyde, and = ((3,5(CF(3))(2)C(6)H(3))(4)B(-))). Electrochemical methods, (57)Fe Mössbauer spectroscopy, electronic spectroscopy, and electron paramagnetic resonance were used for this purpose. Although the anti conformation of the complexes precludes any metal-metal interaction, all the techniques employed show that 3a(+) is a electronic delocalized system, while 3b(+) behaves as two individual metallic centers with localized electron density.

[Fibrolamellar hepatocarcinoma. Case report]

We reported a case with the hystologic diagnosis of fibromellar carcinoma. A 50 year-old woman without known risk factors for hepatocellular carcinoma. She appeared at the hospital with pain in the upper right quadrant, hepatomeglia and weight loss. The automated enhanced tomography evidenced a heterogeneous tumor with a diameter of 15 cm. compromising segments 4, 5, 6, 7 and 8 of the liver. Tumor calcifications and the retraction of the hepatic capsule were identified. Alpha-fetoprotein levels were normal and a negative serology for viral hepatitis were found. The patient underwent a surgical resection (extended right hepatectomy, the partial resection of the main biliary tract and a portal lymphadenectomy). Six months later she is asymptomatic and evidences no recurrence of the disease. The clinical, pathological, radiological features, treatment options and prognoses of fibrolamellar carcinoma were discussed.

Antifungal monoterpene production in elicited cell suspension cultures of Piqueria trinervia

Cell suspension cultures of the traditional medicinal plant Piqueria trinervia Cav., which synthesizes monoterpene piquerol A, were established. A defense response was induced in the cultures when eight homogenized fungi isolated from wild populations of P. trinervia were added. Piquerol A was not produced in the elicited system, while four other substances were synthesized de novo. They were excreted into the medium and inhibited in vitro fungal growth. The most abundant substance produced in this system was a new monoterpene: 2-methylene-7,7-dimethylbicyclo (3,3,1) heptane-4,6-diol. Monoterpenes in the cell suspension culture reported here were produced via two metabolic channels: the first acted constitutively and expressed in liquid and solid cultures, the second is inducible in response to several pathogens and elicitor substances.