癌症,这个让人闻风丧胆的词汇，不仅因为它难以治愈，更因为它带来的痛苦让人难以承受，尤其是到了晚期，疼痛似乎成了癌症病人的“标配”，为什么癌症晚期病人会特别疼？我们就来揭开这场与疼痛的“亲密接触”背后的秘密。
我们要明白,疼痛并不是癌症的“专利”，但癌症晚期的疼痛确实有其独特之处，癌症晚期的疼痛，通常被称为“癌痛”，是一种复杂的、多因素共同作用的结果，它不仅仅是身体上的痛苦，更是心理上的折磨。
肿瘤的直接压迫和浸润
癌症晚期的肿瘤通常会变得很大,甚至扩散到身体的其他部位，这些肿瘤会直接压迫周围的神经、血管和组织，导致剧烈的疼痛，肺癌晚期可能会压迫胸壁神经，引起胸痛；肝癌晚期可能会压迫肝脏包膜，引起右上腹疼痛。
肿瘤还会浸润到周围的组织和器官,破坏正常结构，导致炎症和疼痛，这种疼痛通常是持续性的，且随着肿瘤的增大而加重。
骨转移的“骨痛”
癌症晚期,尤其是乳腺癌、前列腺癌和肺癌，常常会发生骨转移，骨转移不仅会导致骨骼的破坏，还会引起剧烈的骨痛，这种疼痛通常被描述为“钻心”的痛，尤其是在夜间或活动时更为明显。
骨转移引起的疼痛,主要是因为肿瘤细胞破坏了骨骼的正常结构，导致骨骼变得脆弱，甚至发生病理性骨折，肿瘤细胞还会释放一些炎症因子，刺激神经末梢，引起疼痛。
神经病理性疼痛
癌症晚期的病人常常会经历神经病理性疼痛,这种疼痛是由于肿瘤直接侵犯或压迫神经，或者由于化疗、放疗等治疗手段损伤神经引起的，神经病理性疼痛通常被描述为“烧灼感”、“电击感”或“针刺感”，且常常伴有麻木和刺痛。
这种疼痛的特点是难以忍受,且对常规的止痛药物反应不佳，病人常常需要特殊的神经病理性疼痛药物，如抗抑郁药或抗癫痫药，来缓解疼痛。
心理因素的作用
癌症晚期的疼痛不仅仅是身体上的痛苦,心理因素也起着重要的作用，病人常常会感到焦虑、抑郁和恐惧，这些情绪会加重疼痛的感觉，心理因素不仅会影响病人对疼痛的感知，还会影响疼痛的治疗效果。
研究表明,心理干预，如认知行为疗法、放松训练和心理支持，可以显著减轻癌症病人的疼痛，在治疗癌症疼痛时，不仅要关注身体上的疼痛，还要关注病人的心理状态。
治疗手段的副作用
癌症晚期的治疗手段,如化疗、放疗和手术，虽然可以控制肿瘤的生长，但也会带来一些副作用，如疼痛，化疗药物可能会引起周围神经病变，导致手脚麻木和疼痛；放疗可能会引起皮肤和黏膜的炎症，导致疼痛；手术后的伤口疼痛也是常见的。
这些治疗手段的副作用,不仅会影响病人的生活质量，还会加重疼痛的感觉，在治疗癌症疼痛时，需要综合考虑治疗手段的副作用，选择合适的止痛方案。
疼痛的恶性循环
癌症晚期的疼痛常常会形成一个恶性循环,疼痛会导致病人活动减少，肌肉萎缩，关节僵硬，进而加重疼痛，疼痛还会影响病人的睡眠和食欲，导致营养不良和免疫力下降，进一步加重病情。
在治疗癌症疼痛时,不仅要缓解疼痛，还要打破这个恶性循环，帮助病人恢复正常的活动和生活。
止痛药物的选择
癌症晚期的疼痛治疗,通常需要多学科的合作，包括肿瘤科、疼痛科、心理科和康复科等，止痛药物的选择，通常遵循世界卫生组织（WHO）的“三阶梯止痛原则”。
第一阶梯：非阿片类止痛药，如对乙酰氨基酚和非甾体抗炎药（NSAIDs），适用于轻度疼痛。
第二阶梯：弱阿片类止痛药，如可待因和曲马多，适用于中度疼痛。
第三阶梯：强阿片类止痛药，如吗啡、芬太尼和羟考酮，适用于重度疼痛。
还可以使用辅助药物,如抗抑郁药、抗癫痫药和皮质类固醇，来增强止痛效果。
非药物治疗
除了药物治疗,非药物治疗也是缓解癌症疼痛的重要手段，物理治疗，如热敷、冷敷和按摩，可以缓解肌肉和关节的疼痛；心理治疗，如认知行为疗法和放松训练，可以减轻心理压力；康复治疗，如运动疗法和作业疗法，可以帮助病人恢复活动能力。
疼痛的个体化治疗
癌症疼痛的治疗,需要根据病人的具体情况，制定个体化的治疗方案，不同的病人，疼痛的原因、程度和耐受性都不同，因此需要综合考虑病人的病情、身体状况和心理状态，选择合适的止痛方案。
疼痛的长期管理
癌症疼痛的治疗,通常是一个长期的过程，病人需要定期评估疼痛的程度和效果，及时调整治疗方案，病人还需要学会自我管理疼痛，如通过放松训练、呼吸练习和分散注意力等方法，来缓解疼痛。
癌症晚期的疼痛是一个复杂的、多因素共同作用的结果，治疗癌症疼痛，需要综合考虑病人的身体和心理状态，选择合适的止痛方案，通过多学科的合作和个体化的治疗，我们可以帮助病人缓解疼痛，提高生活质量。
英文翻译：
Article Title: Why Do Advanced Cancer Patients Experience Severe Pain? – An "Intimate Encounter" with Pain
Article Content:
Cancer, a term that strikes fear into the hearts of many, is not only difficult to cure but also brings unbearable suffering. Especially in the advanced stages, pain seems to be a "standard feature" for cancer patients. Why do advanced cancer patients experience such severe pain? Today, we will uncover the secrets behind this "intimate encounter" with pain.
First, we need to understand that pain is not exclusive to cancer, but the pain experienced in advanced cancer stages is indeed unique. This pain, often referred to as "cancer pain," is a complex result of multiple factors working together. It is not just physical suffering but also psychological torment.
Direct Compression and Infiltration by Tumors
In advanced stages, tumors usually grow large and may even spread to other parts of the body. These tumors can directly compress surrounding nerves, blood vessels, and tissues, causing severe pain. For example, advanced lung cancer may compress the chest wall nerves, leading to chest pain; advanced liver cancer may compress the liver capsule, causing pain in the upper right abdomen.
Additionally, tumors can infiltrate surrounding tissues and organs, destroying normal structures and causing inflammation and pain. This type of pain is usually continuous and worsens as the tumor grows.
Bone Metastasis and "Bone Pain"
In advanced stages, cancers such as breast cancer, prostate cancer, and lung cancer often metastasize to the bones. Bone metastasis not only destroys bone structure but also causes severe bone pain. This pain is often described as "excruciating," especially at night or during movement.
The pain from bone metastasis is mainly due to tumor cells destroying normal bone structure, making bones fragile and even leading to pathological fractures. Moreover, tumor cells release inflammatory factors that stimulate nerve endings, causing pain.
Neuropathic Pain
Advanced cancer patients often experience neuropathic pain, which is caused by tumors directly invading or compressing nerves, or by damage from treatments like chemotherapy and radiation. Neuropathic pain is often described as "burning," "electric shock," or "pricking," and is usually accompanied by numbness and tingling.
This type of pain is difficult to endure and often does not respond well to conventional painkillers. Patients often require special neuropathic pain medications, such as antidepressants or anticonvulsants, to alleviate the pain.
The Role of Psychological Factors
The pain experienced by advanced cancer patients is not just physical; psychological factors also play a significant role. Patients often feel anxious, depressed, and fearful, which can intensify the perception of pain. Psychological factors not only affect how patients perceive pain but also influence the effectiveness of pain treatment.
Studies have shown that psychological interventions, such as cognitive-behavioral therapy, relaxation training, and psychological support, can significantly reduce cancer pain. Therefore, when treating cancer pain, it is essential to address both the physical pain and the patient's psychological state.
Side Effects of Treatment
Treatments for advanced cancer, such as chemotherapy, radiation, and surgery, while controlling tumor growth, can also cause side effects, including pain. Chemotherapy drugs may cause peripheral neuropathy, leading to numbness and pain in the hands and feet; radiation may cause inflammation of the skin and mucous membranes, leading to pain; post-surgical wound pain is also common.
These side effects not only affect the patient's quality of life but also exacerbate the sensation of pain. Therefore, when treating cancer pain, it is crucial to consider the side effects of treatments and choose appropriate pain relief strategies.
The Vicious Cycle of Pain
Pain in advanced cancer often creates a vicious cycle. Pain leads to reduced activity, muscle atrophy, and joint stiffness, which in turn worsens the pain. Additionally, pain can affect sleep and appetite, leading to malnutrition and weakened immunity, further aggravating the condition.
Therefore, in treating cancer pain, it is essential not only to relieve the pain but also to break this vicious cycle, helping patients regain normal activity and life.
Choosing Painkillers
The treatment of pain in advanced cancer typically requires a multidisciplinary approach, involving oncology, pain management, psychology, and rehabilitation. The choice of painkillers usually follows the World Health Organization's (WHO) "three-step analgesic ladder."
Step 1: Non-opioid analgesics, such as acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), for mild pain.
Step 2: Weak opioids, such as codeine and tramadol, for moderate pain.
Step 3: Strong opioids, such as morphine, fentanyl, and oxycodone, for severe pain.
Additionally, adjuvant medications, such as antidepressants, anticonvulsants, and corticosteroids, can be used to enhance pain relief.
Non-Pharmacological Treatments
In addition to pharmacological treatments, non-pharmacological methods are also important for managing cancer pain. Physical therapies, such as heat and cold packs and massage, can relieve muscle and joint pain; psychological therapies, such as cognitive-behavioral therapy and relaxation training, can reduce psychological stress; rehabilitation therapies, such as exercise and occupational therapy, can help patients regain mobility.
Individualized Pain Treatment
The treatment of cancer pain requires an individualized approach based on the patient's specific circumstances. Different patients have different causes, intensities, and tolerances for pain, so it is essential to consider the patient's condition, physical state, and psychological state when choosing a pain relief strategy.
Long-Term Pain Management
The treatment of cancer pain is usually a long-term process. Patients need regular assessments of pain intensity and treatment effectiveness, with timely adjustments to the treatment plan. Additionally, patients need to learn self-management techniques, such as relaxation training, breathing exercises, and distraction methods, to alleviate pain.
In conclusion, the pain experienced by advanced cancer patients is a complex result of multiple factors. Treating cancer pain requires a comprehensive approach that considers both the physical and psychological states of the patient. Through multidisciplinary collaboration and individualized treatment, we can help patients alleviate pain and improve their quality of life.
