論文の公開元へLocal hyperthermia with built-in endoscopy for radioresistant cervical cancer: a case series
概要
Cervical cancer is the fifth most prevalent cancer in Japanese women, with approx. 10,000
new cases diagnosed annually.1 More than 70% of cervical cancers are squamous cell carcinomas
which are primarily radiosensitive, and thus radiotherapy is often the main treatment modality
for locally advanced cervical cancer. In fact, roughly half of cervical cancer patients undergo
radiotherapy with or without surgery/chemotherapy.1 In cases of recurrence, cervical cancer is
likely to become radioresistant as a consequence of radiotherapy. The subsequent treatment
options are limited, because pelvic irradiation is frequently used as a primary therapy for
cervical cancer. Re-irradiation to the same anatomical site is generally contraindicated, and
systemic chemotherapy is less effective for tumors within a previously irradiated site due to the
reduced vascularity.2,3 It is thus difficult to eradicate recurrence after radiotherapy with additional
radiotherapy or systemic chemotherapy.
The curative surgical procedure for a locoregional recurrence of cervical cancer is total pelvic
exenteration, removing all organs from the pelvic cavity and creating a colostomy. The rate of
perioperative complications for total pelvic exenteration is relatively high, and the indications
should be carefully considered.4 Because of this background, there is a great need for less-invasive
methods to control local recurrences of cervical cancer, especially at irradiated sites.
Artificially raising the local temperature (exogenous thermotherapy) has been used to treat
recurrent cancer. It has also been shown that the combined use of hyperthermia enhances the
effect of chemotherapy in recurrent cervical cancer after radiotherapy.5 Local hyperthermia has
been suggested to be useful for superficial human papillomavirus (HPV)-related lesions.6,7 The
cytotoxic response to hyperthermia depends on protein denaturation, structural changes in intracellular organelles, the induction of apoptosis, and changes in intracellular metabolism.8 In the range
43–45 °C, the main antitumor effects of hyperthermia are coagulation and the denaturation of
proteins as a direct effect and tissue damage secondary to microvascular damage as an indirect
effect.8 Hyperthermia can be used for a wider range of patients than treatments such as surgery
and chemotherapy because it causes less damage to normal tissues and has relatively milder
side effects.
Hyperthermia is expected to become a local treatment for cervical cancer that has recurred
or remained after radiotherapy, but a technique that will heat only the lesion has not been
established. If hyperthermia can be targeted to the lesion on the surface of the cervix of the
uterus or on the vaginal wall, it would not only be more effective but also reduce side effects.
We have developed an innovative laser hyperthermia system consisting of a transvaginal probe
with a tip that can be optimally heated plus built-in endoscopy that can be directed to the tumor.9
Herein, we reported a case series of local thermotherapy with built-in endoscopy for
post-radiotherapy persistent cervical cancer or possible occult residual tumor, to evaluate its
applicability, safety, and efficacy. ...
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