Objective This study investigated whether digital PCR (dPCR)-based circulating tumor DNA (ctDNA) monitoringcan allow longer intervals between computed tomography (CT) scans during postoperative surveillance of colorectal cancer (CRC). Design The longitudinal dynamics of ctDNA for 52 patients with CRC as measured by dPCR using probes targeting 87 individual tumor-specific mutations (1-5 per patient) were compared with results from conventional (i.e., clinical) surveillance using serum tumor markers and CT. A total of 382 CT procedures were carried out for the patient cohort (3.3/year per patient) and the median lead time from ctDNA relapse to clinical relapse was 182 days (range 0-376 days). If the CT interval was annual, potential delays in detection of clinical relapse would have occurred for 7 of the 10 patients who experienced clinical relapse (9 of 13 events), with a median delay of 164 days (range, 0-267 days). If annual CT surveillance was performed together with ctDNA monitoring, 218 (57.1%) CTs would not have been needed to detect the first clinical relapse. Nonetheless, ctDNA monitoring would still have provided a lead time of 339 days for detection of clinical relapse (range, 42-533 days). Conclusion Our findings suggest that the ctDNA monitoring as part of post-operative surveillance and clinical relapse detection for patients with CRC could allow the CT interval to be lengthened.
Abstract The majority of advanced gastric cancer has been treated with 5-fluorouracil (5-FU)-based chemotherapy after complete resection, but a considerable number of patients experience relapse within 5 years after the resection. It has been considered that extremely small drug-tolerant cancer cell subpopulations are responsible for the relapse after chemotherapy. Previously, we established a 5-FU-tolerant gastric cancer cell line, MKN45T, which requires a higher drug concentration to suppress its growth relative to its parental, MKN45. Using the pair of cell lines, we developed an orthotopic xenograft (OX) model that mimics advanced human gastric cancer by transplantation of the cells into the gastric submucosal layer of nude mice. The OX of the 5-FU-tolerant cell line, MKN45T, showed an aggressive tumorigenicity, metastasis, and peritoneal dissemination, in contrast to the parental cell line, MKN45. Proteomic screening using a colony lysate array, a special format of reverse-phase protein array that allows us to quantify the protein levels in individual drug-tolerant subpopulations (i.e., colonies), revealed the level of phosphatidylinositol 3-kinase (PI3K) phosphorylation was increased according to the 5-FU dose-escalation. The prevalence of cells with active PI3K also increased with 5-FU treatment in OX. In contrast, phosphorylation of Akt and mTOR proteins were slightly decreased by the 5-FU treatment. Interestingly, PTEN protein expression was almost completely suppressed in OX after the 5-FU treatment. To see whether PI3K inhibitors have potency in the reduction of tumors with persistent growth after 5-FU treatment, PI3K inhibitors, including LY294002, Queracetin, Wortmannin, GNE493, and GDC0941, were tested by means of colony formation assay. Among them, simultaneous administration of 5-FU and GDC0941 significantly suppressed colony formation, which led us to examine the inhibitory effect of GDC0941 for tumor growth in the OX model. Sequential administration of 5-FU and GDC0941 prohibited the propagation of 83% (5/6) of OX tumors in the stomach as well as other organs. Western blot was then performed to clarify the growth suppression mechanisms by GDC0941 for PI3K-activated tumors triggered by 5-FU. The Akt/PI3K/mTOR and PTEN pathway analysis in response to single/combinational drug administration revealed that the majority (75%, 6/8) of gastric cancer cell lines tested exhibited an increased level of PI3K phosphorylation with 5-FU administration. The increased level of PI3K phosphorylation with 5-FU, which subsequently induces Akt and mTOR activation, was effectively suppressed by GDC0941 administration, particularly with a considerably decreased level of p70 S6 kinase phosphorylation. These results suggest that administration of 5-FU followed by GDC0941 may suppress relapse after complete resection with 5-FU-based chemotherapy for gastric cancer. Citation Format: Satoshi S. Nishizuka, Kaoru Ishida, Yukimi Ohmori, Kohei Kume, Chie Ito, Akari Konta, Yuka Koizumi, Mamoru Nukatsuka, Takashi Kobunai, Teiji Takechi, Takeshi Iwaya. Inhibition of phosphatidylinositol 3-kinase suppresses propagation of drug-tolerant cancer cell subpopulations enriched by 5-fluorouracil. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4671.
Abstract Background Paradoxically, patients with advanced stomach cancer who are Helicobacter pylori -positive (HP + ) have a higher survival rate than those who are HP - . This finding suggests that HP infection has beneficial effects for cancer treatment. Present study examines whether HP + individuals have a lower likelihood of death from cancer than those who are HP - . Methods and findings Prospective cohort data ( n = 4,982 subjects enrolled in the DAIKO study between 2008-2010) was used to assess whether anti-HP antibody status as a surrogate for past-present HP infection was associated with cancer incidence. The median age in the primary registry was 53 years-old (range 34-69 years-old). Over the 8-year observation period there were 234 (4.7%) cancer cases in the cohort and 88 (1.8%) all-cause deaths. Urine anti-HP antibody data was available for all but one participant (n = 4,981; 99.97%). The number of HP + and HP - individuals was 1,826 (37%) and 3,156 (63%), respectively. Anti-HP antibody distribution per birth year revealed that earlier birth year was associated with higher HP + rates. To remove confounding factors associated with birth year, a birth year-matched cohort ( n = 3,376) was generated for subsequent analyses. All-cancer incidence was significantly higher in HP + individuals than those who were HP - (p=0.00328), whereas there was no significant difference in the cancer death rate between HP + and HP - individuals (p=0.888). Strikingly, we found that HP + individuals who developed cancer had a better survival rate than would be expected based on cancer incidence. These results suggest that cancer patients who are HP + may have a higher likelihood of survival than those who are HP - . Cox regression analysis for prognostic factors revealed that the hazards ratio of HP + was 1.59-fold (95%CI 1.17-2.26) higher than HP - in all-cancer incidence. Conclusions Potential systemic effects of HP + status may contribute to reduced likelihood of death for patients with cancer. Data Availability Statement The data cannot be shared publicly as data sharing is not permitted according to Japanese Government data protection policies. Requests for data analysis may be accepted anonymously and conditionally upon IRB approval from Iwate Medical University and Nagoya University Graduate School of Medicine. Funding This study is supported by Grants-in-Aid for Scientific Research for Priority Areas of Cancer (No. 17015018); Grants-in-Aid for Innovative Areas (No. 221S0001); and the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant (No. 19K09130 and No. 16H06277 [CoBiA]) from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests The authors declare that no competing interests exist. Author summary Why was this study done? > Although HP infection is a major cause of gastric diseases including cancer, how HP infection affects prolonged survival of advanced gastric cancer patients is unknown. > Reports of studies carried out in different countries and regions revealed that advanced gastric cancer patients who are HP + exhibited prolonged post-treatment survival, even though the genetic background of patients, HP strains, and cancer treatment procedures differed. > Since most advanced gastric cancer patients underwent gastrectomy, the favorable prognosis of HP + patients after multidisciplinary treatment may be due to putative systematic mechanisms associated with HP infection. > If putative systemic mechanisms associated with HP infection reduce the likelihood of death due to cancer, the cancer survival rate in the HP + population should be lower than that for the HP - population. What did the researchers do and find? > Using data from the DAIKO prospective cohort study in Nagoya, Japan, we analyzed the association between anti-HP antibody status, cumulative cancer incidence and all-cause and cancer-specific deaths. > The HP + rate increased as birth year decreased. Thus, matching based on birth year between 1935 and 1975 was performed to correct for confounding factors associated with birth year. > Despite a significantly higher all-cancer incidence for HP + individuals compared to those who were HP - , no difference in the all-cause and cancer death rate was observed between HP + and HP - individuals. What do these findings mean? > HP + individuals are less susceptible to death relative to their incidence of cancer. > Patients with advanced stage cancer who are HP + may have a better treatment response/tolerance than those who are HP - . > Additional longitudinal analyses are warranted to evaluate the effect of HP + status on prolonged survival of patients with advanced-stage cancer.
Paradoxically, Helicobacter pylori-positive (HP+) advanced gastric cancer patients have a better prognosis than those who are HP-negative (HP-). Immunologic and statistical analyses can be used to verify whether systemic mechanisms modulated by HP are involved in this more favorable outcome.A total of 658 advanced gastric cancer patients who underwent gastrectomy were enrolled. HP infection, mismatch repair, programmed death-ligand 1 (PD-L1) and CD4/CD8 proteins, and microsatellite instability were analyzed. Overall survival (OS) and relapse-free survival (RFS) rates were analyzed after stratifying clinicopathological factors. Cox proportional hazards regression analysis was performed to identify independent prognostic factors.Among 491 patients that were analyzed, 175 (36%) and 316 (64%) patients were HP+ and HP-, respectively. Analysis of RFS indicated an interaction of HP status among the subgroups for S-1 dose (Pinteraction = .049) and PD-L1 (P = .02). HP+ patients in the PD-L1- group had statistically higher 5-year OS and RFS than HP- patients (81% vs 68%; P = .0011; hazard ratio [HR] = 0.48, 95% confidence interval [CI] = 0.303 to 0.751, and 76% vs 63%; P = .001; HR = 0.508, 95% CI = 0.335 to 0.771, respectively). The 5-year OS and RFS was also statistically higher for HP+ compared with HP- patients in the "PD-L1- and S-1-r educed" group (86% vs 46%; P = .001; HR = 0.205, 95% CI = 0.07 to 0.602, and 83% vs 34%; P = .001; HR = 0.190, 95% CI = 0.072 to 0.498, respectively). Thus, HP status was identified as one of the most potentially important independent factors to predict prolonged survival.This retrospective study suggests that an HP-modulated host immune system may contribute to prolonged survival in the absence of immune escape mechanisms of gastric cancer.
Abstract We investigated whether early circulating tumor DNA (ctDNA) changes, measured using digital PCR (dPCR), can predict later chemotherapy responses in esophageal squamous cell cancer (ESCC). We compared the dynamics of ctDNA and tumor volumes during chemotherapy in 42 ESCC. The accuracy of predictions of later chemotherapy responses was evaluated by the ratio of the variant allele frequency of ctDNA (post-/pre-ctDNA) and the total tumor volume (post-/pre-volume) before and after an initial chemotherapy cycle using a receiver-operating characteristic curve analysis. Total positive and negative objective responses (ORs) were defined as either >50 or ≤50% reductions, respectively, in the total tumor volume at the end of first-line chemotherapy. Mutation screening of 43 tumors from 42 patients revealed 96 mutations. The pretreatment dPCR-ctDNA data were informative in 38 patients, using 70 selected mutations (1–3 per patient). The areas under the curve (AUCs) for the post-/pre-volume and post-/pre-ctDNA levels used in predicting the total OR were 0.85 and 0.88, respectively. The optimal cutoff value of post-/pre-ctDNA was 0.13. In 20 patients with post-/pre-volume ≥50%, the total OR could be predicted by the post-/pre-ctDNA with high accuracy; the AUC by post-/pre-ctDNA was higher than that by post-/pre-volume (0.85 versus 0.76, respectively). Patients with low post-/pre-ctDNA (n = 18) had a significantly better overall survival rate than those with high post-/pre-ctDNA (n = 20; P = 0.03). Early ctDNA changes after an initial cycle of chemotherapy predict later responses to treatment with high accuracy in ESCC patients.
Abstract The mainstay of advanced gastric cancer (GC) therapy is DNA-damaging drugs. Using proteogenomic analysis of a panel of eight GC cell lines, we identified genetic alterations and signaling pathways, potentially associated with resistance to DNA-damaging drugs. Notably, 5-fluorouracil (5FU) resistance was associated with PD-L1 expression, but not established GC subtypes. In publicly available cohort data, PD-L1 expression was associated with a reduced risk of GC progression. In addition to PD-L1, expression of inflammatory genes induced by lymphocyte cytokines was consistently associated with prolonged survival in GC. In our validation cohort, total lymphocyte count (TLC) predicted a better relapse-free survival rate in GC patients with 5FU-based adjuvant chemotherapy than those with surgery alone. Moreover, TLC + patients who had no survival benefit from adjuvant chemotherapy were discriminated by IκBα expression. Collectively, our results suggest that 5FU resistance observed in cell lines may be overcome by host immunity or by combination therapy with immune checkpoint blockade.
Corticosteroid insensitive airway inflammation is observed in some patients of chronic obstructive pulmonary disease (COPD) and severe asthma. We previously reported that repeated dosed lipopolysaccharide (LPS) reduced corticosteroid sensitivity in mice. Recently, some groups reported that Src was involved in inflammatory responses in mice models of COPD and asthma. Thus, we determined effects of dasatinib on airway inflammation in mice induced by ovalbumin (OVA) and/or LPS exposure.
Objective: This study investigated whether digital polymerase chain reaction (dPCR)-based circulating tumor DNA (ctDNA) monitoring can allow longer intervals between computed tomography (CT) scans during postoperative surveillance of colorectal cancer (CRC). Background: Practical guidelines still recommend intensive postoperative surveillance of CRC using periodical CT scans and serum carcinoembryonic antigen testing. Methods: The longitudinal dynamics of ctDNA for 52 patients with CRC as measured by dPCR using probes targeting 87 individual tumor-specific mutations (1–5 per patient) were compared with results from conventional (ie, clinical) surveillance using serum tumor markers and CT. Results: A total of 382 CT procedures were carried out for the patient cohort (3.3/year per patient) and the median lead time from ctDNA relapse to clinical relapse was 182 days (range, 0–376 days). If the CT interval was annual, potential delays in the detection of clinical relapse would have occurred for 7 of the 10 patients who experienced clinical relapse (9 of 13 events), with a median delay of 164 days (range, 0–267 days). If annual CT surveillance was performed together with ctDNA monitoring, 218 (57.1%) CTs would not have been needed to detect the first clinical relapse. In addition, the ctDNA monitoring would have provided a lead time of 339 days for detection of clinical relapse (range, 42–533 days). Conclusions: Our findings suggest that the ctDNA monitoring as part of postoperative surveillance and clinical relapse detection for patients with CRC could allow the CT interval to be lengthened. Trial Registration: This trial was registered with University Hospital Medical Information Network Clinical Trial Registry (UMIN000045114).
Abstract Background Paradoxically, Helicobacter pylori- positive (HP + ) advanced gastric cancer patients have a better prognosis than those who are HP-negative (HP - ). Immunologic and statistical analyses can be used to verify whether systematic mechanisms modulated by HP are involved in this more favorable outcome. Methods A total of 658 advanced gastric cancer patients who underwent gastrectomy were enrolled. HP infection, mismatch repair, programmed death-ligand 1 (PD-L1), and CD4/CD8 proteins, and microsatellite instability were analyzed. Overall survival (OS) and relapse free survival (RFS) rates were analyzed after stratifying clinicopathological factors. Cox proportional hazards regression analysis was performed to identify independent prognostic factors. Results Among 491 cases that were analyzed, 175 (36%) and 316 (64%) cases were HP + and HP−, respectively. Analysis of RFS indicated an interaction of HP status among the subgroups for S-1 Dose ( P =0.0487) and PD-L1 ( P =0.016). HP + patients in the PD-L1 group had significantly higher five-year OS and RFS than HP - patients (81% vs. 68%; P =0.0011; HR 0.477; and 76% vs. 63%; P =0.0011; HR 0.508, respectively). The five-year OS and RFS was also significantly higher for HP + compared to HP - patients in the PD-L1 - /S-1-reduced group (86% vs. 46%; p =0.0014; HR 0.205; 83% vs. 34%; p =0.001; HR 0.190, respectively). Thus, HP status was identified as one of the most potentially important independent factors to predict prolonged survival. Conclusion Modulation of host immune system function by HP may contribute to prolonged survival in the absence of immune escape mechanisms of gastric cancer.
