How does chemotherapy work? - Hyunsoo Joshua No

譯者: Ann Lee 審譯者: Helen Chang

During World War I, one of the horrors of trench warfare

一戰期間，壕溝戰的慘狀之一

was a poisonous yellow cloud called mustard gas.

是瀰漫著黃色雲狀 名叫芥子毒氣的有毒氣體。

For those unlucky enough to be exposed,

那些暴露於氣體的倒霉人，

it made the air impossible to breathe, burned their eyes,

氣體讓他們難以呼吸， 灼傷他們的雙眼，

and caused huge blisters on exposed skin.

且在裸露的皮膚上燙出水泡。

Scientists tried desperately to develop an antidote to this vicious weapon of war.

科學家們拚命地研發 這惡性戰爭武器的解藥。

In the process they discovered the gas was irrevocably damaging the bone marrow

他們於過程中發現

氣體侵害的士兵的骨髓，

那些傷害無可挽回，

of affected soldiers— halting its ability to make blood cells.

會阻撓紅血球的生成。

Despite these awful effects, it gave scientists an idea.

撇除這些可怕的影響， 它提供科學家一個點子。

Cancer cells share a characteristic with bone marrow: both replicate rapidly.

癌細胞與骨髓有相同的特點：

兩者都迅速複製。

So could one of the atrocities of war

有人能夠於殘暴的戰爭中

become a champion in the fight against cancer?

成為抗癌的勝利者嗎？

Researchers in the 1930s investigated this idea

研究人員在 1930 年代

把從芥子毒氣萃取出的化合物 注入癌症病人的靜脈，

by injecting compounds derived from mustard gas

into the veins of cancer patients.

深入研究這個想法。

It took time and trial and error to find treatments that did more good than harm,

尋找利大於弊的療法 需要時間和嘗試錯誤，

but by the end of World War II,

在二戰結束之際，

they discovered what became known as the first chemotherapy drugs.

他們發現了第一種化學療法藥物。

Today, there are more than 100.

現今有多於一百種的藥物。

Chemotherapy drugs are delivered through pills and injections

化療藥物藉藥丸和注射劑傳遞，

and use "cytotoxic agents," which means compounds that are toxic to living cells.

並使用「細胞毒劑」， 也就是對活細胞有毒的化合物。

Essentially, these medicines cause some level of harm to all cells in the body—

這些藥物的本質會對所有的 體內細胞造成一定程度的傷害，

even healthy ones.

健康的細胞包括在內，

But they reserve their most powerful effects for rapidly-dividing cells,

但保留最強效的作用 給快速分裂的細胞，

which is precisely the hallmark of cancer.

（快速分裂）正是癌症的標誌。

Take, for example, those first chemotherapy drugs,

舉例來說，那些至今 仍被使用的第一批化療藥物，

which are still used today and are called alkylating agents.

叫做烷化劑。

They’re injected into the bloodstream,

它們被注入血管，

which delivers them to cells all over the body.

好讓它們傳遞至全身的細胞。

Once inside, when the cell exposes its DNA in order to copy it,

一旦抵達，當細胞為了複製 而暴露 DNA 時，

they damage the building blocks of DNA’s double helix structure,

它們會損害 DNA 雙股螺旋狀組件，

which can lead to cell death unless the damage is repaired.

除非細胞的損害已修復， 否則會導致細胞的死亡。

Because cancer cells multiply rapidly,

因為癌細胞可以迅速地複製，

they take in a high concentration of alkylating agents,

它們攝入高濃度的烷化劑，

and their DNA is frequently exposed and rarely repaired.

其 DNA 經常暴露但極少復原。

So they die off more often than most other cells,

所以比其他多數細胞更常相繼死去，

which have time to fix damaged DNA

後者有時間修復受損的 DNA，

and don’t accumulate the same concentrations of alkylating agents.

不會累積相同的烷化劑濃度。

Another form of chemotherapy involves compounds called microtubule stabilizers.

另一種形式的化療涵蓋了 名為「微管穩定劑」的化合物。

Cells have small tubes that assemble to help with cell division

細胞小管的聚集可以幫助有絲分裂，

and DNA replication, then break back down.

以及 DNA 的複製，然後分解。

When microtubule stabilizers get inside a cell,

當微管穩定劑進入一個細胞，

they keep those tiny tubes from disassembling.

它們保護微小的管狀器官免於分解。

That prevents the cell from completing its replication, leading to its death.

這阻止細胞完成複製， 從而導致死亡。

These are just two examples of the six classes of chemotherapy drugs

這只是今日我們用來治療癌症

we use to treat cancer today.

六類化療藥物中的兩個例子。

But despite its huge benefits, chemotherapy has one big disadvantage:

儘管有龐大的好處， 化療有個大缺點：

it affects other healthy cells in the body that naturally have to renew rapidly.

它會波及體內自然 快速更新的其他健康細胞。

Hair follicles, the cells of the mouth, the gastrointestinal lining,

毛囊、口腔細胞、胃黏膜、

the reproductive system, and bone marrow are hit nearly as hard as cancer.

生殖系統和骨髓

所遭受的傷害和癌症一樣大。

Similar to cancer cells, the rapid production of these normal cells

這些快速複製的正常細胞 和癌細胞很像，

means that they’re reaching for resources more frequently—

意味著它們更頻繁地取用資源，

and are therefore more exposed to the effects of chemo drugs.

因此更容易暴露於 化學藥物的作用中，

That leads to several common side effects of chemotherapy,

造成一些常見的化療副作用，

including hair loss, fatigue, infertility, nausea, and vomiting.

包括掉髮、疲勞、不孕、噁心和嘔吐。

Doctors commonly prescribe options to help manage these side-effects,

醫生普遍開處方來解決這些副作用，

such as strong anti-nausea medications.

例如強效的抗噁心藥物。

For hair loss, devices called cold caps can help lower the temperature

感冒膠囊則有助於 降低頭周圍的溫度和控制血壓，

around the head and constrict blood vessels,

以解決掉髮問題，

limiting the amount of chemotherapy drugs that reach hair follicles.

限制化療藥物送至毛囊的總量。

And once a course of chemo treatment is over,

一旦化學療程結束，

the healthy tissues that’ve been badly affected by the drug will recover

受藥物嚴重影響的健康組織會康復

and begin to renew as usual.

並且照常開始更新。

In 2018 alone, over 17 million people world-wide received a cancer diagnosis.

單在 2018 年，

世界上有超過 1700 萬人 得知自己罹患癌症。

But chemotherapy and other treatments have changed the outlook for so many.

但化療和其他療法 改變了許多人的前景。

Just take the fact that up to 95% of individuals with testicular cancer

現在請思考一件事：多虧先進的療法，

survive it, thanks to advances in treatment.

高達 95% 的睪丸癌患者倖存。

Even in people with acute myeloid leukemia— an aggressive blood cancer—

即使在患有急性髓性白血病 （一種激進性血液癌）的人中，

chemotherapy puts an estimated 60% of patients under 60

化學治療也使估計 60％ 的 60 歲以下患者

into remission following their first phase of treatment.

在其第一階段治療後緩解。

Researchers are still developing more precise interventions

研究員仍在開發更精確的介入方法

that only target the intended cancer cells.

只瞄準目標的癌症細胞。

That’ll help improve survival rates while leaving healthy tissues

這將有助於提高存活率，

同時減低留下的 健康組織所受的傷害，

with reduced harm,

making one of the best tools we have in the fight against cancer even better.

使我們擁有的抗癌工具之一

好上加好。