Toshiyuki Sasagawa

Effectiveness of prophylactic HPV vaccines against cervical abnormalities and HPV infection in Japan: The J‐HERS 2021 multicenter study

Abstract This study investigated the efficacy of the prophylactic human papillomavirus (HPV) vaccine, which was initiated between 2009 and 2013 in Japan. The study involved 1529 eligible women aged 16–39 years who visited 11 outpatient clinics in Japan for various reasons. These patients underwent HPV genotype analysis and a Pap test of cervical cell samples. A total of 299 women (19.6%) had received the prophylactic HPV vaccine (bivalent:quadrivalent vaccine ratio = 2:1). Of the 5062 participants in the Japanese Human Papillomavirus Disease Education and Research Survey (J‐HERS 2011), which was conducted in the pre‐vaccination era, 3236 eligible participants were included as controls. In this study (J‐HERS 2021), the highest rate of HPV vaccination (53%) was observed in patients aged 22–27 years. Vaccinated individuals exhibited a 49% rate of protection against low‐grade intraepithelial lesions (LSILs) and atypical squamous cells, not excluding high‐grade squamous intraepithelial lesions (ASCH) or worse (LSIL/ASCH+), and a 100% rate of protection against high‐grade squamous intraepithelial lesions (HSILs) or worse (HSIL+). Significant reductions in HPV16 (95%) and HPV18 (100%) infections were noted, but no differences were observed in HPV6 and HPV11 infections. The prevalences of HPV51 and HPV59 increased with vaccination, although these changes were not confirmed in the comparative study with J‐HERS 2011. Comparing the prevaccination (J‐HERS 2011) and postvaccination (J‐HERS 2021) periods, 43%, 51%, 88%, and 62% reductions in HPV16, HPV18, HPV16/18, and HPV31/58 infection rates were observed, respectively. Similarly, 62% and 71% reductions in LSIL/ASCH+ and HSIL+ rates were noted, respectively. There were 88% and 87% reductions in LSIL/ASCH+ and HSIL+ rates in 16–21‐ and 28–33‐year‐old patients, respectively. Bivalent or quadrivalent vaccines provided 100% protection against high‐grade squamous cell lesions (suggestive of CIN2 or CIN3) in young women aged <39 years at 9–12 years after initiation of Japan's first nationwide HPV vaccination program. Cross‐protection against HPV31 and HPV58 is likely to occur, although some HPV‐type replacements are inconsistent across vaccination regimens. This demonstrates the effectiveness of the HPV vaccine. However, continuous monitoring of cervical cancer and precancer is necessary in younger generations (born 1997–2007), who were rarely vaccinated due to the prolonged suspension of the vaccine recommendations in Japan.

Predictive Value of Various Atypical Cells for the Detection of Human Papillomavirus in Cervical Smears

It is thought that numerous genotypes of human papillomavirus (HPV) are associated with various atypical cells, such as multinucleated cells, koilocytes, binucleated cells, parakeratotic cells, and giant cells, in the cervix. We previously showed the specificity of HPV genotypes for koilocytes and multinucleated cells. Therefore, in this study, we analyzed the association among HPV genotypes and binucleated cells, parakeratotic cells, and giant cells in Papanicolaou (Pap) smears. We detected HPV genotypes and atypical cells in 651 cases of liquid-based cytology with an abnormal Pap smear. The HPV genotypes associated with atypical cells were evaluated using stepwise logistic regression with backward elimination and a likelihood ratio test for model construction. Polymerase chain reaction was used to determine the HPV genotypes in whole liquid-based cytology samples and microdissected cell samples from Pap smear slides. Binucleated cells were significantly associated with HPV genotype 42. Moreover, parakeratotic cells were significantly associated with certain HPV genotypes, such as HPV40. However, it was difficult to detect specific HPV genotypes by the manual microdissection-polymerase chain reaction method despite the presence of binucleated cells and parakeratotic cells. Thus, the presence of binucleated cells, parakeratotic cells, and giant cells in Pap smears may not be predictive of cervical lesions above low-grade squamous intraepithelial lesions or infection with highly carcinogenic HPV genotypes.

The prevalence of VAIN, CIN, and related HPV genotypes in Japanese women with abnormal cytology

AbstractVaginal intraepithelial neoplasia (VAIN) is often found by chance. We investigated the prevalence of VAIN and related human papillomavirus (HPV) types in comparison with cervical intraepithelial neoplasia (CIN). This study enrolled 648 women who were referred to the outpatient clinic of Kanazawa Medical University Hospital for abnormal cytology from January 2009 to January 2019. HPV genotypes were determined using Genosearch‐31 + 4, which can detect 35 different HPV types. Colposcopy was performed at the first visit by an experienced gynecological oncologist. Among 611 subjects with squamous cell lesions, 107 (17.5%) VAIN cases were identified, and 67 (11.0%) women had both VAIN and CIN. Ultimately, 72 VAIN1, 15 VAIN2/3, 203 CIN1, 249 CIN2/3, 32 cervical squamous cell carcinomas (SCC), and one vaginal SCC (Vag‐SCC) were identified. The prevalences of VAIN1, VAIN2/3, and Vag‐SCC were 35.5%, 6.0%, and 3.1% of equivalent cervical lesions, respectively. The VAIN patients were older than the CIN patients (P = .002). About half of the VAIN cases were diagnosed during the follow‐up. Multiple HPV infections were found in 42.9% of the VAIN and CIN patients. HPV52, 16, 51, 53, and 56 were the most common types in VAIN, whereas HPV16, 52, 58, 51, and 31 predominated in CIN. HPV18 was rare in VAIN, HPV58 was more common in CIN than in VAIN, and HPV53 and HPV73 were more common in VAIN. In conclusion, VAIN1 was identified more frequently than we expected. Various HPV types were identified in the vagina, which is likely a reservoir for HPV.

Koilocytic changes are not elicited by human papillomavirus genotypes with higher oncogenic potential

AbstractKoilocytes are considered a common cytopathological effect in patients with human papillomavirus (HPV) infection. Thus, we aimed to elucidate whether koilocytes are common to all HPV infections. Liquid‐based cytology samples from 651 patients with abnormal Papanicolaou (Pap) test results were used to analyze the presence of koilocytes and HPV genotype. HPV genotype was determined in complete liquid cytology samples and microdissected cell samples from Pap smear slides using the uniplex E6/E7 polymerase chain reaction method, which can detect 39 mucosal HPV genotypes. Koilocytes were found in 29.3% (191) of all patients. Logistical regression analysis of diverse HPV genotypes revealed that infections with low‐risk HPV types (HPV‐6b, HPV‐40, HPV‐42, HPV‐61, HPV‐74, HPV‐89, and HPV‐90), probably high‐risk HPV types (HPV‐53 and HPV‐66), and high‐risk types (HPV‐39 and HPV‐56) were significantly associated with the presence of koilocytes. However, HPV‐16, HPV‐18, and HPV‐52, which have higher oncogenic potential, were not found to be associated with koilocytes. These results were confirmed by HPV genotyping using microdissected koilocytes in 27 patients.Most common high‐risk types belonging to α‐9 and α‐7 genotypes appear to rarely induce koilocytic changes. Therefore, koilocytes may provide additional useful information for predicting the risk of progression to high‐grade lesions.

Comparison of Aptima and hybrid capture‐2 HPV tests and Pap test in the referral population in Japan

AbstractThe Aptima human papillomavirus (HPV) test (APTIMA) detects E6‐E7 mRNA in abnormal cells in the uterine cervix. To investigate the accuracy of APTIMA for cervical cancer screening in Japan, 423 subjects, mostly referrals with abnormal cytology or being followed up for cervical intraepithelial neoplasia (CIN)1, were screened using two HPV tests, hybrid capture 2 (HC2) and APTIMA, and by the Pap test. Colposcopy was conducted in all subjects with a positive result in either test type. HPV genotyping was performed by Genosearch‐31.A result of atypical squamous cells‐undetermined significance (ASC‐US) or worse on the HC2 test (ASC‐US‐HC2), and low‐grade squamous intraepithelial lesion (LSIL) or worse (LSIL+) on the Pap test, was regarded as positive. APTIMA (97.5%) was more sensitive than LSIL+ (85.1%) for detecting CIN2 or worse (CIN2+) (McNemar test; p = .0003), and more sensitive (98.6%) than ASC‐US‐HC2 (92.7%) for detecting CIN3+. APTIMA and HC2 had similar sensitivities. HPV genotyping revealed that CIN2/3 with high‐risk HPV (HR‐HPV) was overlooked in five cases by ASC‐US‐HC2, and in four cases by HC2, while no such lesions were missed by APTIMA. Thus, APTIMA might be superior to HC2 for primary HPV screening in Japan. One cancer case positive for HPV67 (potentially high risk, [pHR]) was overlooked by Pap test and both HPV tests, suggesting a need for a new HPV test able to detect pHR‐HPV types.

A retrospective study of immunotherapy using the cell wall skeleton of Mycobacterium bovis Bacillus Calmette-Guérin (BCG-CWS) for cervical cancer

Mycobacterium bovis Bacillus Calmette-Guérin (BCG) has the potential to promote adaptive immunity. We sought to examine the synergistic effect of BCG-CWS vaccination on cervical cancer patients undergoing standard treatments including surgery, chemotherapy, and/or radiation. We retrospectively analyzed 103 patients (13 cases administered with BCG-CWS vaccine and 90 controls without BCG-CWS) who underwent a standard treatment for cervical cancer from 2005 to 2021. The BCG-CWS group underwent repeated intradermal injections of the BCG-CWS vaccine before or immediately after the standard therapy start from 2011 to 2018. The vaccination was repeated weekly for 1 month, and then every 4 weeks thereafter. The effectiveness of the BCG-CWS vaccination on cervical cancer treatment was evaluated by determining the hazard ratios of overall survival between the BCG-CWS group and the control group with multivariate analysis using the Cox model. Hazard ratios between 2 groups were determined after adjustment by clinical parameters including surgery, chemotherapy, radiation, age, clinical stage, presence of human papillomavirus, and pathology. Long-term follow-up revealed a significantly better prognosis (hazard ratio: 0.2108, P = .008 by the Cox model) for patients with cervical cancer in the BCG-CWS group compared to patients in the control group. Among patients with advanced cancer worse than stage IB2, some completely cleared the disease, whereas the others showed long-term survival with recurrence. BCG-CWS therapy appears to be an effective immune adjuvant therapy for cervical cancer, although randomized control studies are needed to confirm this. We also need to clarify the underlying mechanisms slowing the progression of cervical cancer in those receiving this vaccination. This study sheds light on the potential of immunostimulatory drugs such as BCG-CWS and suggests the important role of immunity for cancer elimination in combination therapy.

Chemical Peeling Therapy Using Phenol for the Cervico-Vaginal Intraepithelial Neoplasia

Objective: This study aimed to validate the use of liquid phenol-based chemical peeling therapy for cervical and vaginal intraepithelial neoplasia (CIN and VaIN, respectively), with the goal of circumventing obstetric complications associated with surgical treatment and to determine the factors associated with treatment resistance. Methods: A total of 483 eligible women diagnosed with CIN, VaIN, or both, participated in this study. Participants underwent phenol-based chemical peeling therapy every 4 weeks until disease clearance. Disease clearance was determined by negative Pap tests for four consecutive weeks or by colposcopy. HPV genotyping was conducted at the onset of the study and after disease clearance in select cases. Our preliminary analysis compared the recurrence and persistence rates between 294 individuals who received phenol-based chemical peeling therapy and 189 untreated patients. Results: At 2 years following diagnosis, persistent disease was observed in 18%, 60%, and 88% of untreated patients with CIN1–3, respectively, and <2% of patients with CIN who received phenol-based chemical peeling therapy. Among 483 participants, 10 immune-suppressed patients required multiple treatments to achieve disease clearance, and 7 were diagnosed with cervical cancer. Of the 466 participants, except those with cancer or immune suppression, the number of treatment sessions until CIN/VaIN clearance ranged from 2 to 42 (average: 9.2 sessions). In total, 43 participants (9.2%) underwent surgical treatment. Six patients (1.3%) experienced recurrence of CIN2 or worse, suggesting that treatment failed in 46 patients (9.9%). No obstetrical complications were noted among the 98 pregnancies following this therapy. Factors associated with resistance to this therapy include immune suppression, ages 35–39 years, higher-grade lesions, and multiple HPV-type infections. Conclusions: Phenol-based therapy is safe and effective for CINs and VaINs. Women aged < 35 years and with persistent CIN1 or CIN2 with a single HPV-type infection are suitable candidates for phenol-based chemical peeling therapy. However, this therapy requires multiple lengthy sessions.