**1. Introduction**

Pancreatic cancer is currently the fourth leading cause of cancer-related death and is predicted to be the most common cause of cancer mortality by 2030 [1]. Despite advances in the treatment of pancreatic cancer, prognosis remains extremely poor with 5-year survival of only 8% [2]. The low survival rate is attributed to several factors, such as asymptomatic until the disease develops to an advanced stage, early and extensive metastasis, and high resistance to treatment. Therefore, precision diagnosis and effective treatment is a critical clinical issue.

Currently, commonly employed treatments for pancreatic cancer include surgery, chemotherapy, and radiation therapy. Surgical resection is regarded as the only treatment for curing pancreatic cancer. However, only 15% of pancreatic cancer patients present with disease that are resectable upfront. Chemotherapy is the mainstream treatment for local, advanced and metastatic pancreatic cancer [3]. Among the traditional treatment, chemotherapy is the most advanced modality, especially the target therapy. The role of radiotherapy in pancreatic cancer is still controversial. Although the clinical trial results were disappointing, immunotherapy is the still greatly investigated approaches in pancreatic cancer. The deeper investigation of treatment resistance mechanism and novelty modality development is urgently needed.

### **2. Treatment modality of pancreatic cancer**

At present, commonly employed treatment for pancreatic cancer include surgery, chemotherapy, and radiotherapy. The treatment options depend on the stage of pancreatic cancer. Some emerging therapeutic technologies have yet to mature, such as molecular targeted therapy and immunotherapy.

#### **2.1 Surgical therapy**

Surgical resection is regarded as the only treatment for cure and can result in significantly longer survival of pancreatic cancer. According to the diseased localization and extension, pancreatic cancer is divided into resectable, borderline resectable, or locally advanced. Resectable cases account for 15% of pancreatic cancer patients and this subpopulation is the only potential for cure. However, 5-year survival is at best 20–25%. Borderline resectable cases account for another 5–10%. For some patients with early recurrence or not have the complications of aggressive disease and latent metastasis, neoadjuvant therapy is one alternative measures to reduce the tumor burden and obtain better local control. The proper sequence of surgical therapy and neoadjuvant therapy is the determine factor. Delivering full-dose chemotherapy preoperative therapy may be more effective than postoperative therapy because the resected tumor bed is associated with poor drug delivery. In patients with borderline resectable pancreatic cancer after effective neoadjuvant therapies, the possibility for an R0 resection is higher, and survival of patients who underwent surgical resection is better than that of those who did not [4]. Approximately 30–40% of patients have locally advanced unresectable pancreatic cancer (LAPC) in which tumor is involvement of neighboring blood vessels [5].

#### **2.2 Chemotherapy**

Chemotherapy is the mainstay treatment for advanced and metastatic pancreatic cancer. Fluorouracil and gemcitabine are the first line chemotherapy drugs. However, their clinic effective is still disappointing. In recent years, the National Comprehensive Cancer Network (NCCN) guidelines have recommended two options: one is the FOLFIRINOX regimen of four drug combination (fluorouracil + calcium folate + oxaliplatin + irinotecan), another is the AG regimen of a combination of paclitaxel and gemcitabine [6]. Although the four-drug combination scheme is effective to some extent, its toxicity and side effects are great. Considering the physical strength score of some patients, the application of this scheme is limited. The albumin paclitaxel regimen is relatively safe and has fewer adverse reactions. More and more researches recommend this regimen as the first-line treatment of pancreatic cancer in the future. The following subsets are specially suitable for the albumin paclitaxel treatment, such as neoadjuvant and salvage chemotherapy patients, postoperative adjuvant chemotherapy patients, and advanced chemotherapy patients [7].

#### **2.3 Radiotherapy**

Radiotherapy is always used as a curative treatment for localized cancer or lymph node metastasis, and as a palliative treatment in patients with widespread disease. Overall, nearly 50–60% of patients with cancer receive radiotherapy [8]. The role of radiotherapy in pancreatic cancer is controversial. Multiple clinical trials have been designed to access the role of radiology in pancreatic carcinoma

#### *Advance in Pancreatic Cancer Diagnosis and Therapy DOI: http://dx.doi.org/10.5772/intechopen.94413*

over the last 30 years and mixed results were acquired. According to the LAP-07 trial, no benefit was found to the addition of radiotherapy to gemcitabine for locally advanced pancreatic cancer [9]. The American society of radiation oncology's (ASTRO) guidelines recommended the clinical practice of radiotherapy for high-risk pancreatic cancer patients. It is recommended to conditionally undergo fractional radiotherapy or stereotactic body radiation therapy (SBRT) after chemotherapy in surgically resectable patients. The conditional provision of conventional fractional radiation is recommended in positive lymph nodes and margins were found during surgical resection. Neoadjuvant chemotherapy combined with radiotherapy is conditionally recommended after systemic chemotherapy for patients with resectable boundaries. It is recommended to conditionally concurrent chemo or radiotherapy or SBRT as salvage radiotherapy after systemic chemotherapy in locally advanced patients who are not suitable for surgery. New radiotherapy technology, such as intensity modulated radiation therapy (IMRT), SBRT, with advances in motion management, target delineation, treatment planning, and image guidance, allows for reducing treatment-related toxicities, improving control of micro-metastatic disease and dose escalation, as well as possible synergy between radiation and other therapy. Therefore, there is great potential for radiation to improve future outcomes in pancreatic cancer [10].
