Takashi Iwata

Fertility-sparing trachelectomy for early-stage cervical cancer: A proposal of an ideal candidate

To propose an ideal patient candidate with early-stage cervical cancer for undergoing fertility-sparing trachelectomy. This nationwide, multicenter, retrospective study was conducted by the Japan Society of Obstetrics and Gynecology involving women aged <45 years with clinical stage I-II cervical cancer who had planned fertility-sparing trachelectomy and pelvic lymphadenectomy between 2009 and 2013 (n = 393). Ideal candidates were defined to have a tumor size of ≤2 cm, no lymph node metastasis, no deep stromal invasion, and no high-risk histology (n = 284, 69.6%). Less-ideal candidates were defined to have any one of these four characteristics (n = 109, 30.4%). Propensity score inverse probability of treatment weighting was used to assess survival outcomes. Less-ideal candidates were more likely to undergo hysterectomy conversion (22.9% versus 3.2%), receive postoperative radiotherapy (11.9% versus 0.4%), or chemotherapy (32.1% versus 3.2%) compared with ideal candidates (all, P < 0.05). The weighted model revealed that among those who underwent trachelectomy (ideal candidates, n = 275 and less-ideal candidates, n = 84), less-ideal candidates had significantly decreased disease-free survival (5-year rates: 85.5% versus 95.5%; HR 3.93, 95% CI 1.99-7.74; P < 0.001) and cause-specific survival (92.5% versus 98.6%; HR 5.47, 95% CI 1.68-17.8, P = 0.001) compared with ideal candidates. Similarly, less-ideal candidates were significantly associated with decreased disease-free survival compared with ideal candidates among those who were young age, had small tumors or squamous histology, and underwent surgery alone (all, P < 0.05). Less-ideal candidates had approximately four-fold higher recurrence risk and cancer mortality compared with ideal candidates. Ideal candidates for fertility-sparing trachelectomy for early-stage cervical cancer proposed in our study may be useful as the future framework for developing guidelines for fertility-sparing trachelectomy in Japan.

Development of a prognostic prediction support system for cervical intraepithelial neoplasia using artificial intelligence-based diagnosis

Human papillomavirus subtypes are predictive indicators of cervical intraepithelial neoplasia (CIN) progression. While colposcopy is also an essential part of cervical cancer prevention, its accuracy and reproducibility are limited because of subjective evaluation. This study aimed to develop an artificial intelligence (AI) algorithm that can accurately detect the optimal lesion associated with prognosis using colposcopic images of CIN2 patients by utilizing objective AI diagnosis. We identified colposcopic findings associated with the prognosis of patients with CIN2. We developed a convolutional neural network that can automatically detect the rate of high-grade lesions in the uterovaginal area in 12 segments. We finally evaluated the detection accuracy of our AI algorithm compared with the scores by multiple gynecologic oncologists. High-grade lesion occupancy in the uterovaginal area detected by senior colposcopists was significantly correlated with the prognosis of patients with CIN2. The detection rate for high-grade lesions in 12 segments of the uterovaginal area by the AI system was 62.1% for recall, and the overall correct response rate was 89.7%. Moreover, the percentage of high-grade lesions detected by the AI system was significantly correlated with the rate detected by multiple gynecologic senior oncologists (r=0.61). Our novel AI algorithm can accurately determine high-grade lesions associated with prognosis on colposcopic images, and these results provide an insight into the additional utility of colposcopy for the management of patients with CIN2.

Ancient Evolutionary History of Human Papillomavirus Type 16, 18 and 58 Variants Prevalent Exclusively in Japan

Human papillomavirus (HPV) is a sexually transmitted virus with an approximately 8-kilo base DNA genome, which establishes long-term persistent infection in anogenital tissues. High levels of genetic variations, including viral genotypes and intra-type variants, have been described for HPV genomes, together with geographical differences in the distribution of genotypes and variants. Here, by employing a maximum likelihood method, we performed phylogenetic analyses of the complete genome sequences of HPV16, HPV18 and HPV58 available from GenBank (n = 627, 146 and 157, respectively). We found several characteristic clusters that exclusively contain HPV genomes from Japan: two for HPV16 (sublineages A4 and A5), one for HPV18 (sublineage A1) and two for HPV58 (sublineages A1 and A2). Bayesian phylogenetic analyses of concatenated viral gene sequences showed that divergence of the most recent common ancestor of these Japan-specific clades was estimated to have occurred ~98,000 years before present (YBP) for HPV16 A4, ~39,000 YBP for HPV16 A5, ~38,000 YBP for HPV18 A1, ~26,000 for HPV58 A1 and ~25,000 YBP for HPV58 A2. This estimated timeframe for the divergence of the Japan-specific clades suggests that the introduction of these HPV variants into the Japanese archipelago dates back to at least ~25,000 YBP and provides a scenario of virus co-migration with ancestral Japanese populations from continental Asia during the Upper Paleolithic period.

Clinical availability and characteristics of multigene panel testing for recurrent/advanced gynecologic cancer

Japan's health insurance covers multigene panel testing. This study aimed to determine the potential availability and utility of gene panel testing clinically in gynecologic oncology. We analyzed the characteristics of patients with gynecologic cancer who underwent gene panel testing using FoundationOne Out of 102 patients analyzed, 32, 18, 43, 8, and 1 had cervical, endometrial, ovarian cancers, sarcoma, and vaginal cancer, respectively. Druggable gene alteration was found in 70 patients (68.6%; 21 with cervical cancer, 15 with endometrial cancer, 28 with ovarian cancer, 5 with sarcoma, and 1 with other). The most common druggable gene alteration was PIK3CA mutation (n = 21), followed by PTEN mutation (n = 12) and high tumor mutation burden (TMB-H) (n = 11). TMB-H was detected in 5 patients with cervical cancer, 5 with endometrial cancer, and 1 with endometrial stromal sarcoma. Eleven patients (10.8%) received molecularly targeted therapy according to their gene aberrations. Gene panel testing was mostly performed when the second-line treatment was ineffective. Of all 102 patients, 60 did not have recommended treatment, and 15 died or had worsened conditions before obtaining the test results. Through multigene panel testing, although many patients had druggable gene alterations, 10.8% of them received the recommended treatment. TMB-H was mainly observed in cervical/endometrial cancer, suggesting its potential as a therapeutic biomarker of immune checkpoint inhibitors. Furthermore, patients' prognosis and performance status should be considered before performing the test.

Phase I and II randomized clinical trial of an oral therapeutic vaccine targeting human papillomavirus for treatment of cervical intraepithelial neoplasia 2 and 3

Abstract Background Although many human papillomavirus (HPV)–targeted therapeutic vaccines have been examined for efficacy in clinical trials, none have been translated into clinical use. These previous agents were mostly administered by intramuscular or subcutaneous injection to induce systemic immunity. We investigated the safety and therapeutic efficacy of an HPV-16 E7-expressing lacticaseibacillus-based oral vaccine. Methods In a double-blind, placebo-controlled, randomized trial, a total of 165 patients with HPV-16–positive high-grade cervical intraepithelial neoplasia 2 and 3 were assigned to orally administered placebo or low, intermediate, or high doses of IGMKK16E7 (lacticaseibacillus paracasei expressing cell surface, full-length HPV-16 E7). In the 4 groups, IGMKK16E7 or placebo was administered orally at weeks 1, 2, 4, and 8 postenrollment. The primary outcomes included histopathological regression and IGMKK16E7 safety. Results In per-protocol analyses, histopathological regression to normal (complete response) occurred in 13 (31.7%) of 41 high-dose recipients and in 5 (12.5%) of 40 placebo recipients (rate difference = 19.2, 95% confidence interval [CI] = 0.5 to 37.8). In patients positive for HPV-16 only, the clinical response rate was 40.0% (12 of 30) in high-dose recipients and 11.5% (3 of 26) in recipients of placebo (rate difference = 28.5, 95% CI = 4.3 to 50.0). There was no difference in adverse events that occurred in the high-dose and placebo groups (P = .83). The number of HPV-16 E7–specific interferon-γ producing cells within peripheral blood increased with level of response (stable disease, partial, and complete responses; P = .004). The regression to normal (complete response) rates among recipients with high levels of immune response were increased in a dose-dependent manner. Conclusion This trial demonstrates safety of IGMKK16E7 and its efficacy against HPV-16–positive cervical intraepithelial neoplasia 2 and 3. IGMKK16E7 is the first oral immunotherapeutic vaccine to show antineoplastic effects. Trial registration jRCT2031190034.

Intra-Patient Genomic Variations of Human Papillomavirus Type 31 in Cervical Cancer and Precancer

Human papillomavirus type 31 (HPV31) is detected less frequently in cervical cancer than two major causative types, HPV16 and HPV18. Here, we report a comprehensive analysis of HPV31 genome sequences in cervical lesions collected from Japanese women. Of 52 HPV31-positive cervical specimens analyzed by deep sequencing, 43 samples yielded complete genome sequences of around 7900 base pairs and 9 samples yielded partially deleted genome sequences. Phylogenetic analysis showed that HPV31 variant distribution was lineage A in 19 samples (36.5%), lineage B in 28 samples (53.8%), and lineage C in 5 samples (9.6%), indicating that lineage B variants are dominant among HPV31 infections in Japan. Deletions in the viral genome were found in the region from the E1 to L1 genes, but all the deleted genomes retained the E6/E7 genes. Among intra-patient nucleotide variations relative to a consensus genome sequence in each sample, C-to-T substitutions were most frequently detected, followed by T-to-C and C-to-A substitutions. High-frequency, intra-patient mutations (&gt;10%) in cervical cancer samples were found in the E1, E2, and E7 genes, and all of them were nonsynonymous substitutions. The enrichment of high-frequency nonsynonymous substitutions strongly suggests that these intra-patient mutations are positively selected during the development of cervical cancer/precancer.

Diagnostic accuracy of intraoperative frozen section at radical abdominal trachelectomy for early-stage cervical cancer

Intraoperative frozen section examination is crucial for confirming the oncological safety of radical abdominal trachelectomy (RAT) for early-stage cervical cancer. This study evaluated the diagnostic accuracy of frozen section during RAT at our institution. We retrospectively identified patients with International Federation of Gynecology and Obstetrics 2008 stage IA1-IB1 (tumor size ≤2 cm) cervical cancer treated between 2002 and 2021. In performing RAT, frozen section analysis was routinely performed on uterine surgical margins and grossly enlarged lymph nodes, and was confirmed to be negative. Medical records were reviewed to compare the frozen section diagnoses with the final pathology. Among the 326 patients initially planned to undergo RAT, 298 (91.4%) underwent RAT, while 28 (8.6%) were converted to radical hysterectomy. The histological types were squamous cell carcinoma in 251 (77.0%) patients and adenocarcinoma in 67 (20.6%). Of 361 frozen section for surgical margins, 4 false negatives were identified. Discrepancies were due to freezing artifacts, staining quality on frozen sections, and slight differences in cross-sections between frozen and paraffin-embedded sections. Among 446 intraoperative lymph-node biopsies, one false-negative was recorded. Sensitivities of frozen section examination were 93.5% (58/62) for surgical margins and 94.1% (16/17) for lymph nodes. Lymph-node metastases were identified in systematic lymphadenectomy specimens of 21/326 (6.4%) patients planned to undergo RAT, with 10/21 (47.6%) detected intraoperatively. Lymph-node metastases were found in 7/112 (6.3%) patients without lymph-node biopsy. Frozen section examination during RAT provides satisfactory diagnostic performance, although biopsy of grossly enlarged lymph nodes is an unreliable method.

Serum Free Fatty Acid Changes Caused by High Expression of Stearoyl-CoA Desaturase 1 in Tumor Tissues Are Early Diagnostic Markers for Ovarian Cancer

Ovarian cancer has a poor prognosis and is difficult to detect in early stages. Therefore, developing new diagnostic markers for early-stage ovarian cancer is critical. Here, we developed a diagnostic marker for early-stage ovarian cancer on the basis of fatty acid metabolism characteristics of cancer cells. The expression of various fatty acid metabolizing enzymes such as stearoyl-CoA desaturase 1 (SCD1) was altered in early-stage ovarian cancer tissue compared with that in normal ovarian tissue. Changes in the expression of fatty acid metabolizing enzymes, particularly SCD1, in cancer tissues were found to alter concentrations of multiple free fatty acids (FFA) in serum. We were the first to show that fatty acid metabolic characteristics in tissues are related to the FFA composition of serum. Surprisingly, patients with stage I/II ovarian cancer also showed significant changes in serum levels of eight FFAs, which can be early diagnostic markers. Finally, using statistical analysis, an optimal early diagnostic model combining oleic and arachidic acid levels, fatty acids associated with SCD1, was established and confirmed to have higher diagnostic power than CA125, regardless of histology. Thus, our newly developed diagnostic model using serum FFAs may be a powerful tool for the noninvasive early detection of ovarian cancer. Significance: Measurement of serum FFA levels by changes in the expression of fatty acid metabolizing enzymes in tumor tissue would allow early detection of ovarian cancer. In particular, the SCD1-associated FFAs, oleic and arachidic acid, would be powerful new screening tools for early-stage ovarian cancer.