No abstract

BackgroundIn Japan, the cervical cancer preventative HPV vaccination rate has dramatically declined, directly as a result of repeated broadcasts of so-called adverse events and the resulting suspension of the government’s recommendation. Our previous survey of obstetricians and gynecologists in Japan regarding their opinions toward HPV vaccination revealed that these key specialists were as negatively influenced by the reports of purported negative events as were the general population. Here, we report a 3-year follow-up survey of these clinicians.MethodsWe reused the same questionnaire format as used in our 2014 survey, but added new questions concerning opinions regarding a WHO statement and reports of a Japanese nation-wide epidemiological study related to the adverse events, released in 2015 and 2016, respectively.ResultsThe response rate was 46% (259/567): 5 (16.1%) of 31 doctors had inoculated their own teenaged daughters during the time period since the previous survey, despite the continued suspension of the governmental recommendation, whereas in the previous survey none of the doctors had done so. Among the respondents, the majority claimed awareness of the recent pro-vaccine WHO statement (66.5%), and of the report of a Japanese epidemiological study (71.5%), and a majority affirmed they currently held positive opinions of the safety (72.7%) and effectiveness (84.3%) of the HPV vaccine.ConclusionsOur re-survey of Japan’s obstetricians and gynecologists regarding their opinions about the HPV vaccine found that their opinions have changed, potentially leading to a more positive future re-engagement for HPV vaccination in Japan.

In Japan, the trend for cervical cancer at younger ages has been increasing. As a countermeasure, the HPV vaccine was introduced as a routine vaccination in April 2013. However, the Ministry of Health, Labour and Welfare (MHLW) announced a “Suspension of its active inoculation recommendation for HPV vaccine” in June 2013. In 2016, 32 months after that suspension, we conducted survey via Internet and compared the results with our previous ones conducted at 9 and 23 months after suspension (in 2014 and 2015, respectively). We examined the ‘time-dependent change’ of the ‘intention of mothers to inoculate their daughters with the HPV vaccine’ in terms of efficacy of external decision-making support. 17.5% of mothers in the first survey replied that they would inoculate their daughters under the current circumstances, 12.1% in the second survey, and 6.7% in the third, showing a consistent decrease in willingness over time (p = 0.03, p < 0.01). If the government recommendation were to be reintroduced, 22.5% of mothers in the first survey replied they would inoculate their daughters, 21.0% in the second survey, which indicated no significant difference (p = 0.65) over the first interval; however, this was significantly decreased to 12.2% in the third survey (p < 0.01). Our study revealed that the intention to inoculate their daughters has been declining among Japanese mothers over time triggered by the suspension.

Ovarian cancer is the leading cause of gynecologic cancer-related deaths and novel therapeutic strategies are required. Programmed cell death 1 and programmed cell death ligand 1 (PD-L1), which are key mediators of host immune tolerance, are associated with ovarian cancer progression. Recent evidence indicates the importance of IFNγ-induced PD-L1 for immune tolerance in ovarian cancer. This study aimed to reveal the therapeutic potential of suppressor of cytokine signaling 1 (SOCS-1), an endogenous inhibitor of the Janus kinase (JAK)-STAT signaling pathway, for the treatment of ovarian cancer. IHC assessment revealed that patients with ovarian cancer with high intratumoral STAT1 activation exhibited poor prognosis compared with patients with low STAT1 activation ( < 0.05). Stimulation of OVISE, OVTOKO, OV2944-HM-1 (HM-1), and CT26 cell lines with IFNγ induced STAT1 phosphorylation and PD-L1 expression. Adenovirus-mediated gene delivery (AdSOCS-1) in HM-1 and CT26 cells potently inhibited IFNγ-induced STAT1 phosphorylation and PD-L1 upregulation, similar to the addition of JAK inhibitor I, but failed to inhibit their proliferation. Notably, intratumoral injection of AdSOCS-1, but not AdLacZ, significantly inhibited the tumor growth of HM-1 and CT26 cells subcutaneously transplanted in immunocompetent syngeneic mice. AdSOCS-1 reduced PD-L1 expression on tumors and restored the activation of tumor-infiltrating CD8 T cells. Moreover, the antitumor effect of AdSOCS-1 was significantly attenuated by PD-L1 Fc-fusion protein administration , suggesting that the effect of AdSOCS-1 is mainly attributable to enhancement of tumor immunity. This study highlights the potential clinical utility of SOCS-1 as an immune checkpoint inhibitor..