Akira Sugezawa

Prophylactic portal infusion chemotherapy as adjuvant therapy for the prevention of metachronous liver metastasis in colorectal cancer

The DNA ploidy and DNA indices (DI) of 414 patients with colorectal cancer were analyzed, and the incidence of patients with metachronous liver metastasis was found to be significantly higher in those with aneuploid tumors and a DI above 1.5 than in those with aneuploid tumors and a DI below 1.4, or in those with diploid tumors and a DI equal to 1.0. Next, to confirm the effectiveness of administering prophylactic portal infusion chemotherapy (PPIC) as adjuvant therapy for the prevention of metachronous liver metastasis in colorectal cancer, a randomized controlled trial of PPIC was performed on 110 consecutive patients with primary colorectal cancer who had undergone curative resection. Although the incidence of patients with metachronous liver metastasis in the two study groups was not significantly different at 3.3% in the PPIC group and 10.3% in the control group, the incidence in the patients with aneuploidy and a DI above 1.5 was significantly lower in the PPIC group than in the control group. These findings suggest that colorectal cancer with aneuploidy and a DI above 1.5 may have a strong tendency to metastasize to the liver, and that prophylactic portal infusion chemotherapy may be effective for preventing metachronous liver metastasis in such patients.

DNA index as a significant indicator of lymph node metastasis and local recurrence of rectal cancer

To confirm the prognostic significance of the DNA index (DI) in cases of rectal cancer, the nuclear DNA content of tumor cells was examined in 184 cases of rectal cancer treated with curative surgery, and the incidence of lymph node metastasis and recurrence of the cancer was analyzed. The incidence of lymph node metastasis was 43.9 percent in cases with aneuploidy (DI above 1.5), being statistically different from the 18.0 percent incidence in cases with diploidy (P<0.001). Although the extent of lymph node metastasis was limited to adjacent lymph nodes in cases with diploidy, distant lymph node metastases were frequent in cases with aneuploidy, especially in those with a DI above 1.5. Furthermore, the incidence of recurrence of cancer, and especially of local recurrence, was significantly higher (P<0.001) in cases with aneuploidy (DI above 1.5) than in cases with diploidy and aneuploidy (DI below 1.4). These findings indicate the significant value of the DNA index for the prediction of lymph node metastasis and local recurrence in patients with rectal cancer.

Possible Mechanism for the Cocarcinogenic Effect of Bile Acids: Increased Intracellular Uptake of Methylcholanthrene by C3H/10T1/2 Fibroblasts in vitro

The cocarcinogenic effect of bile acids on the chemical transformation of C3H/10T1/2 fibroblasts was examined in vitro. The assimilation of 3H-methylcholanthrene (3H-MCA) by C3H/10T1/2 cells pretreated with bile acids was examined by the measurement of uptake and by autoradiography. Cells that were pretreated for 48 h with bile acids (100 microM lithocholic acid, 500 microM cholic acid) and then maintained in medium that contained 3H-MCA showed an increase in radioactivity compared to control cells. These results indicate that the transfer of carcinogens into cells is enhanced by pretreatment with bile acids.

Clinicopathological features of advanced gastric cancer detected by periodic mass screening

We have attempted to clarify the clinicopathologic features of advanced gastric cancers that were detected in periodic mass screening by comparing them with those of cancers detected by an initial mass screening. The macroscopic type of the cancers detected by periodic mass screening included Borrmanns type 3 in 47% of cases but was an unclassifiable type because of its resemblance to early cancer in gross appearance in another 47% of cases. The predominant histologic type of the cancers was found to be poorly differentiated adenocarcinoma with scirrhous growth. From these results, advanced gastric cancers that resemble early cancers of the depressed type, in gross morphology, and which are histologically diagnosed as poorly differentiated scirrhous carcinoma, are assumed to be rapidly growing tumors. Therefore, some of the cases that have these characteristics may, in fact, represent early-phase scirrhous carcinoma, diffuse carcinoma classified as Borrmanns type 4, of the stomach.

An Atomic Bomb Survivor Patient with Multiple Carcinomas and Dysplasias of Small Intestine.

症例は66歳の男性で, 20歳の時に原爆に被爆, 40歳の時に直腸癌のため直腸切断術を施行された.今回, 上行結腸のIIa様病変ならびに腸閉塞症状が認められたため開腹手術を受けた.空腸に全周性の腫瘍が認められ, 空腸の部分切除ならびに回盲部切除が施行された.切除標本の検索では空腸にBorrmann2型様の癌腫ならびに2個のIIc様異型上皮巣が認められた.術後, 残存小腸の精査によって, 十二指腸ならびに空腸に多発するIIc様病変が認められた.このため再手術が施行され, 十二指腸水平脚のIIa+IIc様の癌腫と, 25個のIIc様異型上皮巣が認められた.DNA ploidy patternの検討では, 空腸, 十二指腸の癌腫はいずれもaneuploidyであり, 正常十二指腸粘膜ならびにIIc様異型上皮巣の大半もaneuploidyであった.本症例は小腸に同時性に多数の上皮性腫瘍が発生したまれな症例であり, 被爆との関連も考えられた.

A comparison of pelvic retroperitoneal pneumography and computed tomography in the assessment of extramural invasion of rectal carcinoma

Pelvic retroperitoneal pneumography (PRP) and pelvic computed tomography (CT) were performed on 33 patients with rectal carcinoma in order to compare the usefulness of the two diagnostic procedures in the preoperative assessment of local malignant extramural invasion. Six PRP-negative patients in whom no free air was visualized in the retroperitoneal space surrounding the mass, were all assessed as having extramural invasion by CT scan and all had histologic evidence of invasion. Of 27 PRP-positive patients in whom free air was seen surrounding the mass, 18 were diagnosed as having extramural invasion on CT, 15 of whom had histologic proof of invasion. In the remaining 9 PRP-positive patients, there was no evidence of extramural invasion on the CT scans, but 5 patients showed evidence of invasion histologically. PRP, when positive, had an unacceptably high rate of being false positive and was therefore unreliable in assessing extramural invasion, whereas CT was able to detect, to some extent, extramural invasion which PRP failed to demonstrate. Based on these findings, we conclude that CT is more useful than PRP in the preoperative assessment of extramural invasion of rectal carcinoma, but is of limited diagnostic value when negative.

Relationship between the size of lesions and intramural spread of gastric cancer. With particular reference to the features of carcinoma of the upper portion of the stomach.

下部胃癌123例, 中部胃癌101例, 上部胃癌50例につき粘膜面からみた肉眼的癌巣の広がり (肉眼的癌巣面積) と組織学的にみた癌巣の広がり (組織学的癌巣面積) を比較し, 壁深達度との関係を検討した. 肉眼的癌巣面積と組織学的癌巣面積はよく相関しており, 組織学的癌巣面積が16cm2以下の場合, 進行癌の占める割合は下部胃癌15/102 (14.7%), 中部胃癌19/73 (26.0%), 上部胃癌18/33 (54.5%) と上部胃癌で有意に高く, 同じ大きさの胃癌であっても胃上部の癌はより進行した癌が多かった. さらに, 全摘胃を用いて粘膜筋板の厚さを胃の各部位ごとに測定したところ, 胃上部ほど粘膜筋板は薄く, 粘膜筋板が癌の壁深達に何らかの関わりをもっている可能性が示唆された.