Abstract
Cancer is the rapid proliferation of abnormal body cells caused by mutation as a result of biological, environmental and dietary factors. Oesophageal cancer is of global health concern due to the advanced stage of the disease during diagnosis and the associated high mortality rate. Oesophageal cancer presents itself either as squamous cell carcinoma (OSCC) or adenocarcinoma. Dysplasia precedes oesophageal squamous cell cancer while Barrett’s oesophagus is present at the onset of oesophageal adenocarcinoma. Early screening is deemed a cost effective approach compared to curative treatment. Unfortunately, most of the devices for screening are not adequately available in some regions and especially in Third World countries. Efforts are underway to create awareness and educate people on preventive measures to be used for keeping oesophageal cancer at bay. The incidence of oesophageal cancer is high in various parts of the world, but for the purposes of this paper, China will be the region of focus.
Introduction
Oesophageal cancer is a lethal human malignancy associated with a high mortality rate. It is ranked the eighth cancer in relation to prevalence and sixth with regard to death rate. More than 480,000 people are diagnosed with oesophageal cancer each year. Out of these number, 400, 000 people die (Hagen et al., 2012). There has been good progress towards adequate staging of this disease, but 25% of patients who undergone primary surgery have a poor 5 year survival rate. In the recent times when lifestyle diseases are such a menace and rapidly rising, the same is happening for oesophageal cancer and especially oesophageal adenocarcinoma. Squamous cell carcinoma, however, has remained stagnant. This insinuates that more scientific research is required to come up with more innovative ways to deal with oesophageal cancer and related lifestyle illnesses. According to Hagen et al. (2012), the 5 year survival rate does not go beyond 40%. Lao-Sirieix & Fitzgerald (2012) advocate the use of screening procedures to increase it. Other programmes used to address the issue of oesophageal cancer are curative and palliative programmes. The objective of curative programmes is to heal and prevent future recurrences while palliative care aims at prolongation of life. This paper discusses the pathogenesis of oesophageal cancer in relation to the population affected, the effects of disease and therapy, and prevailing interventions.
Community or Aggregate
Some studies show variation in the survival rate of oesophageal cancer attributed to ethnicity. However, the delineation of this has not been adequately presented. China is the region that has the highest incidences of oesophageal since it accounts half of the world’s oesophageal cancer cases. During diagnosis, oesophageal cancer is usually overt and incurable in 50% of the patients. Oesophageal cancer is determined by various factors, according to Wu et al. (2011). Lifestyle factors, such as alcohol consumption and tobacco smoking, are major etiological factors that manifest. Consumption of hot beverages and food, high intake of carcinogenic substances such as pickled vegetables, eating food at a rapid rate and nutrition deficiency are suggested etiological dietary factors in high incidence areas of China and Iran. Coupled with genetic predispositions that trigger the occurrence of oesophageal cancer, the risk of suffering from this disease is heightened. In addition, diets that are low in fruits and vegetables are also etiological factors for oesophageal cancer (Wu et al. 2011).
In China, according to a study by Wu et al. (2011), genetic factors aggravate the risk of familial aggregation of oesophageal cancer. This study indicates that an individual is at risk of oesophageal cancer if a first degree relative is diagnosed with this cancer. Some risk factors can be altered by familial predisposition since some risk behaviours, like rapid eating, are characteristic of a certain family. The following factors have been pointed out as essential parameters to consider in the prevention of oesophageal cancer: healthy eating and healthy food choices, smoking and alcohol control, and early detection. The search for indolent cancers is more fruitful compared with waiting to fight off an already mature and invasive cancer (Lao-Sirieix & Fitzgerald, 2012). The rationale for oesophageal cancer preference in particular regions and ethnic groups can be explained in what Bashash et al. (2011) refer to as tumour-host interactions. Differences in these interactions are evident in the “micro-architecture of tumours and the dynamic metastasis process” as influenced by host genetic polymorphisms (Bashash et al., 2011, p. 164). Ethnicity also dictates lifestyle and environmental characteristics; hence, certain ethnic communities are more predisposed to risk factors of cancer in comparison to other communities. However, Bashash et al. (2011, p. 164) suggests that the current immigration processes could result in a “healthy migrant effect” associated with better survival.
Effects
The effects of oesophageal cancer are not only restricted to pathology, but also include social and economic effects. The effects of oesophageal cancer begin from the mere thought of having oesophageal cancer due to psychological and mental distress. In addition, costs required for screening and therapy could affect the family expenditure. This is further aggravated by the fact that the affected party might be the sole bread-winner; hence, loss of livelihood and income. Some people are forced to rely on well-wishers, and children may be forced to drop out of school due to lack of school fees (Lao-Sirieix & Fitzgerald, 2013). According to BBC News (2013) on health, the prognosis for cancer after therapy is generally bad because many people become disabled or face poor health. This news went on further to state that one in four patients encounter long-term effects of pain, chronic fatigue, sexual and urinary difficulties due to damage of healthy cells during therapy. The most common effect of oesophageal cancer after therapy is a high mortality rate as in the case with combined chemotherapy during palliative care. In addition, He et al. (2013) state that an indwelling venous access is necessary to ensure that there is a continuous infusion of 5-FU, and it acts as a causative factor for venous thrombosis and sepsis. This makes therapy an unbearable and arduous experience to the patients. There have been recent developments to investigate the effects of “taxanes (paclitaxel and docetaxel), capecitabine, nedaplatin, oxaliplatin, vinorelbine, capecitabine, and irinotecan” either singly or in combination (He et al., 2013, p. 5913).
In a meta-analysis review by Kranzfelder, Schuster, Geinitz, Friess & Buchler (2011), complications during and after neoadjuvant treatment were recorded and ranged between 2% to 78%. There were reported incidences of postoperative morbidity and the most common cases were cardiopulmonary complications and anastomotic leakage. These complications result in increased length of hospital stays and increased hospital costs. Hagen et al. (2012, p. 2078-2080) study shows that patients receiving chemoradiotherapy experienced the following side effects: “anorexia, constipation, alopecia, diarrhoea, vomiting, neutropenia, fatigue, oesophagitis, oesophageal perforation, thrombocytopenia, and neurotoxic effects”. In one patient, perforation of the oesophagus, leading to eventual death, was assumed to be a consequence of this kind of therapy since there was no thrombocytopenia. After surgery, the following postoperative events were recorded: pulmonary complications, chylothorax, cardiac complications, anastomotic leakage and mediastinitis. Pulmonary complications included pneumonia, pleural effusion, pulmonary embolus, pneumothorax and acute respiratory failure. Cardiac complications entailed myocardial infarction, left ventricular failure and arrhythmia.
Interventions
Oesophageal squamous cell carcinoma and oesophageal adenocarcinoma are the salient types of oesophageal cancer that should be treated differently, yet most current research studies combine the two and treat them as one. Preventive procedures, especially early screening and seeking prompt treatment, are the most effective ways to avoid the detrimental effects of oesophageal cancer. Screening helps to detect the preinvasive cancer. Initially, oesophagectomy was deemed the sole effective mode of therapy until mucosal resection and mucosal ablation techniques were developed, whose risks of associated comorbidities are lower compared to those of oesophagectomy. Endoscopy is the salient screening technique. The most effective dysplasia-enhancing chromoendoscopy technique is the Lugol’s iodine staining according to Lao-Sirieix & Fitzgerald (2012). Another screening technique is ultrathin endoscopy. This is deployed via the nose and no sedation is required. It is suggested that there is increased tolerability with regard to this screening method.
Video capsule endoscopy is still another screening technique that is useful for viewing and recording images at the lower oesophagus; hence, more effective in detecting oesophageal adenocarcinoma compared to oesophageal squamous cell carcinoma. Curative therapies for squamous oesophageal cancer include neoadjuvant treatment that is defined by either chemotherapy or chemoradiotherapy with subsequent surgery (Kranzfelder, Schuster, Geinitz, Friess & Buchler, 2011). In some instances, chemoradiotherapy is effective when used alone. As earlier noted, staging procedures for oesophageal cancer are adequately effective, for example endoscopy with biopsy. These improved diagnostic and staging techniques enable doctors and other health workers to get accurate results. It also ensures that candidates are appropriately selected for different modes of treatment to attain optimal health outcomes.
According to Kranzfelder, Schuster, Geinitz, Friess & Buchler (2011, p. 768) “surgical resection with enough lymphadenectomy” is the recommended treatment for resectable OSCC. There have been consistent debates over the role of neoadjuvant chemoradiotherapy for several years due to inconsistencies between theory and findings. Randomized trials have not shown any benefit derived from this mode of treatment, but the research design procedures have been highly criticized. Meta-analyses studies, however, show the converse of this. These are the reasons that prompted Hagen et al. (2012) to engage in a randomized trial that further investigated the effects of neoadjuvant chemoradiotherapy and surgery in comparison to surgery alone. The study showed better health and survival outcomes among patients who underwent neoadjuvant chemoradiotherapy using carboplatin and paclitaxel, then surgery compared with the control group. This preoperative treatment led to reduced morbidity and early mortality after the surgery.
As a matter of fact, those who underwent preoperative treatment had a 34% lowered risk of mortality (Hagen et al., 2012). The best pathological outcome recorded for chemoradiotherapy was complete remission in both the lymph nodes and the actual cancer. The authors justify their results, saying that their study had focused on oesophageal patients only while other research studies had included gastric cancers as well, yet the two cancers are different in their pathophyisology. The meta-analysis study review by Kranzfelder, Schuster, Geinitz, Friess & Buchler (2011) shows mixed results. It shows positive results when preoperative treatments are used to treat OSCC. The reason for these positive results is improved methods during staging of oesophageal cancer and focus on just one kind of oesophageal cancer: OSCC. However, the review does not give clear results with regard to neoadjuvant chemotherapy compared to surgery alone. The use of combined therapies is associated with mixed health outcomes; hence, clear scientific evidence is required.
Regardless of various positive and hopeful results that have been demonstrated by various studies, He et al. (2013) state that there is no standard chemotherapy regimen for advanced cases of oesophageal cancer. Patients with metastatic or recurrent OSCC are usually placed on palliative care while using systematic combined chemotherapy. There are various regimens of chemotherapy used to help prolong life and improve the quality of life. The most common chemotherapy combined regimen is “10 mg/m2 of cisplatin per day and 5-FU (1000mg/m2 per day continuous infusion for 96-120h)” (He et al., 2013, p. 5913). This combined form of therapy has been rendered more effective compared to when either one of the drug is used alone. In a study by He et al. (2013) to investigate the combined effect of paclitaxel and platinum in patients with metastatic oesophageal cancer, encouraging anti-tumour activity was recorded. Treatment related toxicities should be used in restricted amounts, in view of performance status and tolerance of chemotherapy among individuals with metastatic oesophageal cancer.
Bashash et al. (2011) classify prognostic factors for oesophageal cancer into three categories: tumour-related, host-related and environment-related. Tumour-related prognostic factors are based on staging of the disease, which greatly determines the mode of treatment to be used. Tumour topography is pointed out as a predictive factor for survival. Different ethnic groups will have different tumour topographies, and genetic predisposition also influences the topography of the tumour. Host-related prognostic factors are in relation to genetic variation as well as differences in the mode of treatment administered to an individual. Environmental prognostic factors entail availability and accessibility to healthcare, and lifestyle.
My Position on the Subject
Oesophageal cancer is a lethal disease because a high number of individuals who get the disease do not survive due to the detrimental effects of the disease itself and therapy. Oesophageal cancer is associated with such fatal consequences as inability to eat due to a blocked oesophagus, or pain when swallowing. As a result, individuals are not able to eat and will mainly die due to poor nutrition. This is further aggravated by the side effects of therapy as mentioned earlier. The Chinese and Iranian people have been mainly highlighted as populations susceptible to oesophageal cancer, yet no particular study shows specific distinguishing parameters that predispose them to this disease. There have been many developments in the mode of interventions (diagnostic and therapeutic). Different therapies therefore are proposed for the treatment of oesophageal cancer depending on staging. However, there is still some confusion with regard to the use of combined therapy. Until now, there is no conclusive evidence as to whether neoadjuvant chemotherapy is more beneficial compared to surgery alone due to controversial research findings from different studies. Relentless efforts in research on obtaining effective interventions for oesophageal cancer aimed at lowering the high mortality rate are still ongoing. The public needs to be highly sensitized on effective preventive measures like early screening. Governments on the other hand should make these screening services available to citizens at subsidized and more affordable rates.
References
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He, Y., Chu-Shu, J., Hu, B., Fan, P., Hu, C., Jiang, F., … & Wang, W. (2013). A phase II study of paclitaxel and nedaplatin as front-line chemotherapy in Chinese patients with metastatic esophageal squamous cell carcinoma. World J Gastroenterology, 19(35), 5910-5916.
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