2 | CASE REPORT
A 43-year-old Japanese woman with UCC was referred to the Department of Radiation Oncology from the Department of Gynecology for definitive radiotherapy. Histological analysis of the biopsy specimen showed the presence of tumor cells with enlarged nuclei and pale-to-clear cytoplasm exhibiting sheet-like growth and stromal infiltration (Figure 1 ). Immunohistochemical analysis of the biopsy specimen showed positivity for p16, p53, and p63, leading to the diagnosis of squamous cell carcinoma. In line with the pathological diagnosis, the patient showed high levels of serum squamous carcinoma antigen (SCC, 19.0 ng/ml; normal, <1.5 ng/ml). Genotyping of the biopsy specimen showed positivity for human papillomavirus (HPV) type-31. Bimanual pelvic examination revealed bilateral parametrium involvement not reaching the pelvic sidewalls and the absence of vaginal involvement. Magnetic resonance imaging detected a tumor (61 × 60 × 75 mm) located in the uterine cervix with slightly increased intensity on T2-weighted images extending to the bilateral parametria (Figure 2A, B ). Computed tomography (CT) showed lymphadenopathy in the external iliac-, common iliac-, and para-aortic-lymph node (PALN) regions (Figure 3A–C ). 2-deoxy-2-[18F]fluoro-D-glucose (FDG)-positron emission tomography (PET) showed abnormal FDG uptake in the primary tumor (Figure 2C ) and in the involved lymph nodes (Figure 3D–F ). The CT and FDG-PET examinations showed no evidence of metastasis to distant organ sites. The patient was diagnosed as Stage IIB based on the 2008 definition by the International Federation of Gynecology and Obstetrics.
The patient had a high-grade fever (39.1°C) with no symptoms of infection. Blood tests showed a high white blood cell (WBC) count (28.3 × 103/mm3; normal, 3.0–9.0 × 103/mm3) and high levels of serum C-reactive protein (CRP, 6.21 mg/dl; normal, < 1.5 mg/dl). Immature granulocytes suggestive of leukemia were not detected in the peripheral blood. Serum G-CSF was abnormally high (323 pg/ml; normal, <39 pg/ml). Based on these data, the clinical diagnosis was G-CSF-producing tumor.
The patient received concurrent chemoradiotherapy using cisplatin. Radiotherapy consisted of external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT). EBRT was administered as follows: (i ) whole pelvic irradiation with 50 Gy in 25 fractions (the last 20 Gy was delivered using a central shielding technique); (ii ) prophylactic irradiation targeting PALN regions at a dose of 40 Gy in 20 fractions; and (iii ) boost irradiation to the enlarged lymph nodes (8 Gy in four fractions for pelvic lymph nodes and 16 Gy in eight fractions for PALNs). ICBT was delivered at a dose of 24 Gy in four fractions. Cisplatin (40 mg/m2) was administered weekly for a total of three cycles starting on day 29 after improvement of the fever and inflammatory response. The patient completed the radiotherapy regimen as planned (Figure 4 ). The overall treatment time was 49 days.
After completion of the treatment, the tumor achieved almost complete response as assessed by the Response Evaluation Criteria in Solid Tumors (version 1.1) (Figure 5 ). Serum G-CSF and SCC levels improved to within normal limits (36.5 pg/ml and 0.8 ng/ml, respectively). The patient experienced the following acute adverse effects as assessed by the Common Terminology Criteria for Adverse Effects (version 4.0): nausea (Grade 3), leukopenia (Grade 3), neutropenia (Grade 3), diarrhea (Grade 2), anemia (Grade 2), and thrombocytopenia (Grade 1). These adverse effects improved to Grade 0 within 2 months after completion of the treatment.
The patient developed a fever (38.3°C) 2 months after completion of the treatment. CT examination showed multiple metastases to a left supraclavicular lymph node, the liver, and the lung (Figure 6 ). The patient was considered ineligible for chemotherapy because of the high inflammatory response (CRP, 18.30 mg/dl) and was provided with best supportive care. CT performed 4 months after completion of the treatment showed no evidence of in-field recurrence. Serum G-CSF was not assessed after the metastases; however, a remarkably high WBC count (104.8 × 103/mm3) suggested that the G-CSF-producing property of the tumor was preserved at the metastatic sites (Figure 7 ). The patient expired from disease progression 5 months after completion of the treatment. Permission for an autopsy was not granted from the relatives at the time of mortality.
To better understand the biological basis of this aggressive tumor, we analyzed mutation profiles. DNA was extracted from a pre-treatment biopsy specimen in which the tumor cell content was higher than 50%. The exons of 409 cancer-related genes (Supplementary Table 1 ) were sequenced using the Ion AmpliSeq Comprehensive Cancer Panel (Thermo Fisher Scientific, Waltham, MA, USA). After quality filtering, the number of sequencing reads per sample was 15.8 million, and the coverage depth was 945 reads per base (Supplementary Table 2 ). Somatic mutations were identified using the analytical pipeline described previously14. Sixteen non-synonymous (Table 1 ) and four synonymous mutations were identified. The mutation spectrum in a three-base context did not represent the APOBEC signature (i.e., enrichment of substitution of a C preceded by a T into either T, G, or A) typical of HPV-associated cancers15 (Figure 8 ). Of the 16 non-synonymous mutations identified, PIK3C2B(T879N), KDR (V297I), and TET2 (P29R) were registered in the Catalogue of Somatic Mutations in Cancer16 as recurrent mutations.