While the article mentions that things like the high rate of smoking among Palestinians (22% of all adults) and the use of chemical pesticides in farms may account for some of this increase, it spends three paragraphs saying that Israel could be to blame for much of it.
Because Israel is accused of using depleted uranium in the recent wars in Gaza.
In 2009, the IAEA said that it would investigate claims that Israel used DU in the first Gaza war. Israel said it would cooperate with the investigation. I cannot find any results.
One NGO claimed to have found evidence of a ridiculous 75,000 kg of DU dropped in Gaza. That study was released by the impartial sounding "Action of Citizens for the total Dismantling of Nukes" and paid for by the Arab Commission on Human Rights. The study itself is a joke and provides no evidence at all. Which tells you a lot more about how NGOs can create whatever they are asked for rather than a reflection of any facts.
I've also investigated a report that Israel used DU in a Syria airstrike, and found that the claims were simply made up.
Yet Arabs keep making the accusation, and over time it gains currency among the usual haters and no one actually does any investigations.
Why Israel's alleged use of DU in Gaza would increase cancer among Arabs in the West Bank is just one of those mysteries that another NGO will need to find a reason for. Perhaps they will discover that Jews are poisoning the wells.