Tadao Nagayama
Chiba University
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Featured researches published by Tadao Nagayama.
The Journal of Urology | 2001
Tatsuo Igarashi; Toyofusa Tobe; Hiroomi Nakatsu; Noriyuki Suzuki; Shino Murakami; Masaaki Hamano; Masayuki Maruoka; Tadao Nagayama; Osamu Matsuzaki; Haruo Ito
PURPOSE The 1997 TNM classification defines T1 tumors as those smaller than 7 cm. Recently, a cutoff point of 4 cm. has been proposed to create a subclass of T1 tumors. We evaluated the validity of this cutoff point by assessing the pathological findings and prognoses of patients with T1N0M0 renal cell carcinoma following radical nephrectomy. MATERIALS AND METHODS We reviewed the hospital charts of 333 patients with T1N0M0 tumors, followed as long as 282 months (median 63) after radical nephrectomy. The validity of tumor size cutoff point for predicting survival outcome was tested in relation to other prognostic factors, including patient age, tumor position, nuclear grade, tumor histopathology and degree of microscopic venous invasion. RESULTS During followup 32 patients (9.6%) had tumor recurrence and 21 (6.3%) died of renal cell carcinoma. A 5 cm. cutoff point maximized the differences in cancer specific survival rates and a 4 cm. cutoff point maximized the differences in disease-free survival rates. Tumor size was directly related to microscopic venous invasion and nuclear grade, which are significant prognostic factors, and a 4 cm. cutoff point enhanced these relationships. CONCLUSIONS Tumor size is an important prognostic factor for patients with T1N0M0 renal cell carcinoma. A cutoff point of 4 cm. is practical for dividing the T1N0M0 classification into T1a and T1b subclasses.
Pathology International | 2008
Takeichiro Kuwahara; Tadao Nagayama
Fifty cases (20 cases of benign hyperplasia, 30 cases of adenocarcinoma) of prostatic tissues were studied for expression of keratin. The basal cells were strongly and continuously positive in normal prostatic glands and in benign prostatic hyperplasia. The secretory cells and carcinoma cells were negative. The basal cells remained partially in intra‐ductal carcinoma, revealing keratin positive cells in a spotty pattern. These findings may be useful in differential diagnosis between benign prostatic hyperplasia and carcinoma of the prostate.
International Journal of Urology | 2005
Masayuki Maruoka; Masaaki Fujimura; Koji Kawamura; Sumie Suzuki; Masaaki Hamano; Yasuyo Nishikawa; Tadao Nagayama
Abstract Purpose: Thirty‐nine renal cell carcinoma patients with bony metastasis were intensively treated, primarily with immunotherapy using natural type interferon‐α (IFN‐α) continuous subcutaneous injection in combination with surgical resection and radiation therapy. Long‐term survival was achieved, including three patients with complete response. The results of this study are presented.
The Japanese Journal of Urology | 1991
Masayuki Maruoka; Takehiko Miyauchi; Tadao Nagayama; Takeichirou Kuwahara
Seventy-seven patients with primary malignant testicular tumors were treated in our hospital. Twenty-five of them were given antineoplastic agents containing cis diamine dichloro platinum (CDDP). In three long-term survivors, new malignant testicular tumors developed meta-chronously and had different histological findings from those of the initial tumors. Case 1. A 28-year-old patient with a yolk sac tumor of the left testicle, stage IIO, developed metastasis to the supraclavicular lymph nodes five years after radiation. Chemotherapy containing of VP-16 (837 mg), CDDP (1050 mg), vincristine (32 mg), bleomycin (480 mg), and actinomycin-D (16 mg) achieved complete remission. Four years 11 months later a seminoma of the contralateral testicle, stage I, was disclosed and he died of cancer 11 years and four months after the onset of the initial disease. Case 2. A 30-year-old patient with testicular teratoma, stage IIIA, on the right side gained complete remission after a CDDP containing chemotherapy. One year and four months after the beginning of the CDDP use (1,300 mg totally as CDDP) a seminoma on the contralateral side, stage I, was detected. He died of cancer eight years and two months after his initial tumor was detected. Case 3. A 37-year-old patient with combined tumor of seminoma and yolk sac tumor of the right testicle, stage IIIO, was free from disease for six years and five months under chemotherapy. At this point a seminoma, stage I, of the contralateral testicle was newly found and treated by radiation.(ABSTRACT TRUNCATED AT 250 WORDS)
The Japanese Journal of Urology | 1992
Takehiko Miyauchi; Tadao Nagayama; Koshi Maruyama
The Japanese Journal of Urology | 1995
Masayuki Maruoka; Yasuyo Nishikawa; Takehiko Miyauchi; Tadao Nagayama
The Japanese Journal of Urology | 1987
Masayuki Maruoka; Takehiko Miyauchi; Tadao Nagayama; Takeichiro Kuwahara
低温医学 = Low temperature medicine | 2004
Masayuki Maruoka; Tadao Nagayama
Endocrinologia Japonica | 1981
Teruhiro Nakada; Hidekazu Shigematsu; Tadao Nagayama; Takehiko Miyauchi; Yutaka Yoshida; Shigeru Sakiyama; Takashi Katayama; Fumiyuki Shimada
The Japanese Journal of Urology | 1998
Masayuki Maruoka; Masaki Hamano; Yogiro Kobayashi; Yasuyo Nishikawa; Tadao Nagayama