Oncology Frontier: India is one of the countries with the highest incidences of gastric cancer. What can you tell us about gastric cancer screening in India?

　　《肿瘤瞭望》：印度作为胃癌的高发国家之一，请问你们国家是如何进行胃癌筛查的呢？

　　Dr Chandramohan: The incidence of gastric cancer is India can be divided into north， south， east and west as the incidence in different geographical locations varies. The highest incidence of gastric cancer in India is in the Aizawl district in the state of Mizoram where it affects 64.2 people per 100000 population. High incidence areas are classified as being where there is a 30-35 per 100000. The general incidence is anywhere from 5.6-15 per 100000 head of population. I come from the southern part of India from the state of Tamil Nadu where the incidence is 12.2 per 100000. The lowest state incidence is 1.1 per 100000. So incidence can be as low as 1.1 to as high as 64.2 within the same country. We have done analyses on the factors that contribute to the incidence of gastric cancer. Our work was published at IGCC in Korea in 2011 on the impact of lifestyle on gastric cancer in the Indian population. We found the main factor was tobacco in any form. The next was high salt intake. And after that was reused oil (repeatedly using oil for cooking). Then comes the probable role of Helicobacter pylori infection， but that is still debatable. Other than that， there are certain groups where the incidence is very common like the family cancer syndromes， polyps in the stomach， previous surgery on the stomach for benign disease， which after many years can develop as remnant carcinoma or gastric stump carcinoma. With all of these factors in mind， if you ask me about routine screening feasibility， I would say it is neither feasible nor cost-effective. Understanding the incidence as I have outlined， if you want to detect one gastric cancer by routine endoscopic screening， it would prove to be very expensive. Nor would that screening be accessible by all the people notably those who live in rural communities. So we could aim at doing selective screening by choosing the areas that are high incidence areas and investigating the lifestyles of those people who are prone to developing malignancy and screening is performed for those high-risk patients. That would be more feasible and cost-effective.

　　Dr Chandramohan: 在印度不同地理位置胃癌的发病率也不同，可分为北部、南部、东部和西部这四种发病率。胃癌发病率最高的地方是印度米佐拉姆邦处地区，它的发病率达到了每100000人中有64.2人。高发病率地区被列为每100000人中有30～35人。一般的发病率是每100000人中5.6～15人。我是来自印度南部的泰米尔纳德邦，那里发病率是每100000人中12.2人。最低的地方发病率是每100000人中1.1人。所以在同一个国家发病率可以低至1.1也可以高至64.2。我们所分析引起胃癌发病的因素。我们关于生活方式在印度人口中对胃癌影响的工作在2011年韩国IGCC发表。我们发现的主要因素是烟草，另一个就是高盐摄入量，接下来就是用过的油（反复使用的烹饪用油）。然后可能还有幽门螺杆菌感染的作用，但这仍然是有争议的。除此之外，有一些特定人群，他们的发病率也很高，比如家族型胃息肉，以前胃良性疾病做过手术，经过多年发展为残余癌或胃腺癌。考虑到所有这些因素，如果你问我关于常规筛查的可行性，我认为它既不可行也不划算。如我所描述如何理解发生率，如果你想通过常规内镜筛查胃癌，这被证明是非常昂贵的。也不是所有人都能接受这种内镜检查，尤其是那些生活在农村地区的人们。所以我们可以选择高发区域针对性地对高危患者做内镜筛选并且调查这些人容易得恶性肿瘤的生活方式，这将是更加可行和具有成本效益。

　　Oncology Frontier: That is the approach from a governmental perspective. What about an individual physician treating their patients? When should a doctor perform gastric cancer screening on a patient?

　　《肿瘤瞭望》：您刚才的方式是从政府角度出发，那么，如果是从医生个人的角度呢？在实践中，医生在什么时候对患者进行胃癌筛查比较合适？

　　Dr Chandramohan: A doctor who is interested in managing gastric cancer needs to make a diagnosis in the very early stage. The average age of patients with gastric cancer in India is 70 years， but we have also done a study on the incidence in the under 40-year-old population which we have published at this conference. Anybody who is a potential high-risk candidate (polyps in the stomach， H. pylori positivity for a long period， previous endoscopy showing atrophic gastritis， previous surgery on the stomach on benign disease， presenting with symptoms like dyspepsia) should be scoped so the disease can be detected even before it develops symptoms. At this time， we usually see a T3 or T4 metastatic disease as the common presentation in the Indian population.

　　Dr Chandramohan: 对胃癌治疗感兴趣的医生应该在胃癌的早期阶段做出诊断。在印度的胃癌患者的平均年龄是70岁，但在这个会议上我们也发表对40岁以下人群发病率的研究。每一个潜在的高风险候选人（胃息肉，很长一段时期幽门螺杆菌阳性，内镜显示萎缩性胃炎，以前接受过手术的胃良性疾病，表现消化不良等症状）都应该在这个范围里，因此可以在疾病症状之前就发现疾病的存在。现在，在印度人口我们们通常最常见就是T3和T4期转移性疾病。

　　Oncology Frontier: So you wouldn’t screen based on lifestyle choices?

　　《肿瘤瞭望》：所以，你们不会根据生活方式选择来进行筛查？

　　Dr Chandramohan: No. We don’t do routine screening at all. The incidence of gastric cancer running in families is close to 10%. Direct family members of patients are screened， but not others.

　　Dr Chandramohan: 不。我们不做常规筛查。在整个家庭中胃癌的发病率是接近10%。所以我们直接筛选患者的家属，而不是其他没有血缘关系的人。

　　Oncology Frontier:  What is the current five-year survival rate for gastric cancer in India?

　　《肿瘤瞭望》：目前印度的胃癌5年生存率和无疾病进展生存期是多少？

　　Dr Chandramohan: Compared to countries like Japan and Korea， gastric cancer in India is diagnosed at a stage where it is locally advanced or with metastatic disease at the time of first presentation. There are centers with structured follow-up programs using registries where follow-up is up to 90% of operated patients. Then there are centers where there is no structured program and follow-up is dramatically lower. India is developing a distinct urban， suburban and rural population. For rural populations， the follow-up strategies for them to come to the primary team at a treatment center on a regular basis are less developed. So there are two major issues. Firstly， advanced disease survival to five years is less. Secondly， to give accurate data on the number of survivors is difficult because only those registries and centers having stringent rules on follow-ups will have that data available. But from the available data on the Indian population that we have， end of first-year survival is 34.5-35.7%. End of third-year survival drops to 13.2-14.6%. End of five-year survival is 8.6-10.1%. This is contrary to what is seen in Japan and Korea where they have routine screening supported by the government， where the five-year survival exceeds 50% compared to our <10%. This can be attributed to first presentation at an advanced stage of disease and lack of follow-up. A third contributing factor in India would be that death due to all communicable disease needs to be officially notified， but gastric cancer comes under non-communicable disease， so there is the possibility that the death certificate does not carry the diagnosis of gastric cancer as cause of death. This is a problem in other countries also where non-communicable diseases are not properly reported on the death certificate.

　　Dr Chandramohan: 第一次演讲中我曾提到与日本和韩国等国家相比，在印度大多数胃癌诊断时都是局部晚期或转移性疾病的阶段。在有系统的随访的癌症中心，手术后90%患者会接受随访。在没有系统随访的机构这个随访率显著降低。印度是一个独特的发展中国家，它包括城市、郊区和农村人口。对于农村人口，对于他们定期来治疗机构接受随访是相对较困难的。所以现在存在两个重大问题。首先，进展期疾病的五年生存率更少。其次，给出准确的数据是困难的，因为只有那些注册中心和拥有严格随访跟进数据的中心才有这些数据。但从关于印度人可用的数据得出，一年生存率是34.5%～35.7%，三年生存率下降至13.2%～14.6%，五年生存率只是8.6%～10.1%。这是和日本、韩国的结果完全相反的，在政府常规筛查的支持下，日本和韩国的五年生存率超过50%，而我们却低于10%。这可以归因于大多数人确诊时就是一个进展期疾病和缺乏后续的随访数据。在印度，第三个因素是由于所有传染病死亡需要正式通知，但胃癌属于非传染性疾病，所以死亡证明中可能并不携带诊断胃癌的死因。这是一个在其他非传染性疾病不报道在死亡证明中的国家也存在的问题。

　　Oncology Frontier: For locally advanced unresectable gastric cancer patients， what is the role of pre-operative concurrent chemotherapy in improving resectability rates?

　　《肿瘤瞭望》：对于局部晚期不能手术切除的胃癌患者，您认为术前同步放化疗对于提高手术可切除率的作用如何？

　　Dr Chandramohan: Neoadjuvant therapy can either be chemotherapy or chemoradiotherapy. Many centers across the world use chemoradiotherapy as a neoadjuvant strategy， but in India， the majority of centers use only chemotherapy. The most important difference to understand though is the advanced stage of disease that the majority of patients present in. Our analysis has spanned four decades and first published in 1995 at the first international gastric cancer conference in Kyoto. We are presenting our latest paper at this conference regarding the shift in site of gastric cancer and the findings are that， in India， distal gastric cancer remains the commonest form. I tell you this because when distal gastric cancer is common and presents at an advanced stage， it is very common for patients to have symptoms of outlet obstruction. The patient will not be able to eat and be vomiting. It is not uncommon to have perforation or bleeding as complications. In these scenarios， we cannot subject patients to neoadjuvant therapy because surgery has to be done first. If there is obstruction， it has to be relieved either by resection surgery or bypass surgery， and then they can subjected to chemotherapy Similarly， perforated cancers and bleeding cancers which cannot be managed by endoscopic techniques also should be operated on first. Having said that， lesions that are locally advanced in the proximal stomach and gastroesophageal junction and potentially resectable， these patients are candidates for neoadjuvant therapy， which in the Indian setting is chemotherapy. We reassess the patient at the end of three cycles of chemotherapy looking at the progression and size of the tumor before considering surgical resection. That is the strategy used by the majority of centers in India， including our own center.

　　Dr Chandramohan: 新辅助治疗可以是化疗也可以是放化疗。在世界上的很多癌症中心都是采用放化疗作为一种新辅助治疗的方案。但是在印度，大多数的癌症中心只是采用化疗方案作为新辅助治疗。对于如何理解这里面的重要差别主要是因为我们的绝大数患者都是进展期胃癌患者。我们的研究跨越40年，第一次结果发表在1995年的第一个国际胃癌会议上。在这次大会上我们展示的最新研究结果是关于胃癌的远处转移和发现在印度远端胃癌仍是最常见的形式。我告诉你这个是因为对于常见的晚期远端胃癌，患者很容易出现出口梗阻的症状。患者无法进食，会有呕吐的症状，穿孔或出血等并发症并不少见。在这种情况下，患者不能接受新辅助治疗，因为首先需要接受的是手术治疗。如果有梗阻，必须解除通过手术切除病灶或手术改道，然后他们才可以接受化疗。同样，不能由内窥镜技术处理的出血穿孔的癌症患者也应该第一时间手术治疗。我已经说过，如果病变是局部进展期的近端胃癌和胃食管结合部的肿瘤是可以切除的。在印度这些患者接受新辅助治疗主要就是化疗。在三个周期的化疗后我们重新评估患者的肿瘤进展和大小来考虑是否需要手术切除。在印度大多数的中心都是使用这样的策略，这也包括我们自己的中心。