The purpose of this study is to evaluate the clinical effectiveness of Gemcitabine/S-1 combination chemoradiotherapy with Gemcitabine /S-1 combination chemotherapy for unresectable locally advanced pancreatic cancer.

When cancer develops outside of the pancreas from within the anatomical placement of the pancreas itself, it becomes difficult to excise in most cases. Generally, most pancreatic cancers are already unresectable at the time of diagnosis when we have recognized infiltration of over 1/2 the circumference of major arteries such as the celiac artery and super mesenteric artery in particular.

In comparison with advanced pancreatic cancer with distant metastases, it is not easy to treat unresectable locally advanced pancreatic cancer, even when performing standard gemcitabine monotherapy. In the case of unresectable locally advanced pancreatic cancers without distant metastases, we are left with the choice of whether or not to perform radiation therapy. This decision remains unsolved worldwide, despite the continuing efforts of researchers to bring an end to the clinical doubt.

We will report our results as well as the problems of combining treatments with chemoradiotherapy, using the novel anticancer agent gemcitabine as well as/or S-1, not 5FU, predominantly from our own clinical trials on this occasion.

Inclusion Criteria:

1. Histologically or cytologically confirmed adenocarcinoma, adenocarcinoma squamous carcinoma of pancreatic cancer.

2. Patients who confirmed unresectable locally advanced pancreatic cancer with the criteria below.

   • Involving over 1/2 circumference of major artery (SMA/CA). (Under 1/2 that was borderline lesion.)
   • Involving over the merging section of portal-SMV.
   • No distal metastasis with diagnostic imaging.
   • Confirmed by CT image performed with in four weeks before registration.

3. Performance Status:0-1(ECOG)

4. Patients of age =>20 and 80>

5. sufficient organ functions

   • neutrophils>=1,500/mm3
   • platelets>=100,000/mm3
   • hemoglobin>=9.0g/dl
   • AST(GOT)/ALT(GPT) <=150IU
   • total bilirubin <=2.0mg/dl, (or <=3.0mg/dl if biliary drainage were present)
   • serum creatinine <= 1.2mg/dl
   • creatinine clearance>=60ml/min

6. Life expectancy more than 3 months.

7. Written informed consent.

Exclusion Criteria:

1. Lung fibrosis or intestinal pneumonia, and anamnesis or imaging findings.
2. Watery diarrhea
3. Severe infection
4. Severe complication (heart failure, renal failure, hepatic insufficiency,hemorrhagic peptic ulcer, intestines paralysis,ileus or uncontrolled diabetes etc)
5. Massive pleural or abdominal effusion.
6. Metastasis to central nervous system.
7. Active synchronous or metachronous malignancy other than carcinoma in situ.
8. Regular use of flucytosine, fenitoin or warfarin
9. Pregnant or lactation women, or women with known or suspected pregnancy and men who want let to pregnancy
10. Severe mental illness
11. Patients who are judged inappropriate for the entry into the study by the investigator.