癌痛何来?
一直以来,都市人闻癌色变,除了是被“癌症是不治之症”这根深蒂固的错误观念所影响之外,也是源于对癌症所引起的痛楚生成恐惧。
根据研究显示,77%的晚期癌症病人患有癌痛[1]。癌痛可以是由肿瘤本身导致的,当中以胰腺癌较常引起痛症[2]。然而,癌痛最普遍的原因是癌细胞转移到骨骼,引起骨痛[3]。各种癌症当中,最常见发生骨转移的是肺癌、乳癌及前列腺癌[4]。另外,亦有部分癌症的肿瘤会导致肠塞,因而造成痛症[5]。痛症大多于晚间发生,虽然一般不会持续疼痛,但无论如何也会影响病人作息及睡眠质素。
部份病人误以为放射治疔和化学治疔会引起痛症,这其实是误解。上述治疔本身并不会直接引起痛楚,然而,倘接受放射治疔期间,放射线触及口腔或咽喉,会导致黏膜损伤而引起痛楚[6]。
引导病人量化痛楚
相信每个人都曾经承受过不同程度的疼痛。疼痛是主观感觉,也是难以量化的抽象概念。医生通常会引导病人为痛楚评分,以火烧的痛楚为十分,没有痛楚为零分作标准,病人一般可以一至十分表达其疼痛程度。唯对于未能清楚表达其疼痛程度的少数病人,医生仍可根据临床诊断时病人的症状和表情去估计病人所承受的疼痛程度。
纾缓癌痛,一般以处方止痛药物为主,有时亦会辅以放射治疔,以放射线集中照射疼痛位置,减轻痛楚[7,8]。例如癌细胞转移到骨骼所引起的骨痛,会以放射线集中照射骨骼;倘癌痛是由胰腺引起的话,放射线便会针对胰腺。
事实上,经过适当的治疔後,大部份病人的癌痛是可以受到控制的。而病人的睡眠质素大部份能有所提升,生活质素亦可以得到改善。
- Chung JW et al. Acta Anaesthesiol Sin. 1999 Mar;37(1):9-14.
- Signs and symptoms of pancreatic cancer. American Cancer Society. Available at: http://www.cancer.org/cancer/pancreaticcancer/detailedguide/pancreatic-cancer-signs-and-symptoms. Accessed on 2 Nov 2015.
- The Management of Pain in Metastatic Bone Disease. Medscape Oncology. Available at: http://www.medscape.com/viewarticle/761904. Accessed on 2 Nov 2015.
- Coleman RE. Metastatic bone disease: clinical features, pathophysiology and treatment strategies. Cancer Treat Rev 2001;27:165–76.
- Bowel obstruction. Cancer Research UK. Available at: http://www.cancerresearchuk.org/about-cancer/coping-with-cancer/coping-physically/bowel/types/blocked-bowel. Accessed on 2 Nov 2015.
- Treatment and procedures. Cleveland Clinic. Available at: http://my.clevelandclinic.org/health/treatments_and_procedures/hic_Radiation_Therapy_for_Breast_Cancer/hic-radiation-therapy-side-effects-esophagitis-and-mucositis. Accessed on 2 Nov 2015.
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- Local treatment for bone metastasis. American Cancer Society. Available at: http://www.cancer.org/treatment/understandingyourdiagnosis/bonemetastasis/bone-metastasis-local-treatments. Accessed on 2 Nov 2015.